The CB15 terminal board connects to the DB15 connector on applicable LabJacks (not the U12). It provides convenient screw terminal access to the 12 digital I/O available on the DB15 connector. The CB15 is designed to connect directly to the LabJack (see image below), or can connect via a standard 15-line 1:1 male-female DB15 cable (not included).

The green LED on the CB15 is directly powered by the 5-volt supply (Vs) from the LabJack, so it should be lit whenever the CB15 is connected to a powered LabJack.

The CB15 PCB is mounted to a piece of Snaptrack. The Snaptrack is DIN rail mountable using TE Connectivity part #TKAD (not included).

For more information about the I/O lines, see the User’s Guide for the applicable LabJack. Here are a few useful links:

• U3 Section 2.5 (Flexible I/O)
• U3 Section 2.8 (Digital I/O)
• U3 Section 2.11 (DB15)
• U6 Section 2.8 (Digital I/O)
• U6 Section 2.12 (DB15)
• UE9 Section 2.9 (Digital I/O)
• UE9 Section 2.13 (DB15)

Table 1. DB15 Pinouts and Names

Notes:
1.  3" Snap-Track not shown.

Common neutral format CAD models are provided below.  Right-click and select the "Save link as..." option to download STEP files. 

Datasheet Revision 1.02, 2/4/2002

The CB25 Provides screw terminal connections, with short-circuit/overvoltage protection, for the extra 16 digital I/O on the LabJack U12.

The green LED on the CB25 is directly powered by the +5V supply, so it should be lit whenever the CB25 is connected to an active LabJack U12.

D0-D15 – These are connections to the 16 lines of digital I/O. Each has a 1.5kΩ series resistor (R0-R15) for short-circuit/overvoltage protection, and a jumper (J0-J15) to short that resistor. In general, the jumpers will not be installed unless you are using a particular line to output more than 1 mA. See the specifications section of the LabJack U12 User’s Guide for more information on the D lines.

Short-Circuit/Overvoltage Protection: The LabJack U12 has diodes from each D line to each power rail. These diodes clamp the voltage seen by the LabJack to about 5.7 volts maximum and -0.7 volts minimum, but external resistors are required to limit the current to 25 mA (200 mA total for all 16 lines). The CB25 provides 1.5kΩ resistors for this purpose. Taking 1.5kΩ * 25 mA, we get a maximum voltage drop of 37.5 volts so the maximum safe voltage that can be handled by each D line is about 37.5 + 5.7 = 43.2 volts (the minimum safe voltage is about -38.2 volts). Note, however, that the power dissipated by the resistor in this situation is ((0.025)^2)*1500 = 0.94 watts. Since these are ¼ watt resistors you will not be able to block this maximum voltage continuously. The maximum continuous voltage drop is about (0.25 * 1500)^0.5 = 19.4 volts so the maximum safe continuous voltage that can be handled by each D line is about 19.4 + 5.7 = 25 volts (the minimum safe continuous voltage is about -20 volts).

+5V – These are the same as the +5V connection on the LabJack U12. They are a 5 volt source (output), so do not connect another power source to these terminals.

GND – These are the same as the GND connection on the LabJack U12.

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address:3232 S Vance St STE 200, Lakewood, CO 80227 USA
Declares that the product
Product Name: CB25 Terminal Board
Model Number: CB25
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements
EN 61000-4-2: 1995
EN 61000-4-3: 1995
and is marked with CE.

Datasheet Revision 1.01, October 5th, 2006

The CB37 terminal board connects to the LabJack UE9’s DB37 connector and provides convenient screw terminal access. The CB37 is designed to connect directly to the LabJack, but can also connect via a 37-line 1:1 male-female cable (not included). The CB37 V1.2 is not compatible with LJTick signal conditioning modules (CB37 V2.1 required for LJTick compatibility).

The green LED on the CB37 is directly powered by the 5-volt supply (Vs) from the LabJack, so it should be lit whenever the CB37 is connected to a powered LabJack.

The CB37 PCB is mounted to a piece of Snaptrack. The Snaptrack is DIN rail mountable using Tyco part #TKAD (not included).

When using the analog connections on the CB37, the effect of ground currents should be considered, particularly when a cable is used and substantial current is sourced/sunk through the CB37 terminals. For instance, a test was done with a 6 foot cable between the CB37 and a LabJack UE9, and a 100 ohm load placed from Vs to GND on the CB37 (~50 mA load). A measurement of CB37 GND compared to UE9 GND showed 5.9 mV. If a signal was connected to AIN0 on the CB37 and referred to GND on the CB37, the UE9 reading would be offset by 5.9 mV. The same test with the CB37 direct connected to the UE9 (no cable) resulted in an offset of only 0.2 mV. In both cases (cable or no cable), the voltage measured between CB37 AGND and UE9 GND was 0.0 mV.

When any sizeable cable lengths are involved, a good practice is to separate current carrying ground from ADC reference ground. An easy way to do this on the CB37 is to use GND as the current source/sink, and use AGND as the reference ground. This works well for passive sensors (no power supply), such as a thermocouple, where the only ground current is the return of the input bias current of the analog input. Another option is to use a separate ground wire for loads requiring substantial current.

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 3232 S Vance St STE 200, Lakewood, CO 80227 USA
Declares that the product
Product Name: CB37 Terminal Board
Model Number: CB37
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements

The CB37 terminal board connects to the DB37 connector on the LabJack U6, UE9, or T7, and provides convenient screw terminal access. The CB37 is designed to connect directly to the LabJack (see image below), but can also connect via a 37-line 1:1 male-female cable (not included). Since the CB37 V2.1 has screw-terminals with the same IO/IO/GND/VS arrangement as the U6/UE9/T7 itself, it is compatible with LJTick signal conditioning modules.

The green LED on the CB37 is directly powered by the 5-volt supply (Vs) from the LabJack, so it should be lit whenever the CB37 is connected to a powered LabJack.

The CB37 PCB is mounted to a piece of Snaptrack. The Snaptrack is DIN rail mountable using TE Connectivity part #TKAD (not included).

On older CB37 boards, PIN2 was labeled TX0, and PIN20 was labeled RX0.

On the U6/T7, PIN2 and PIN20 are current sources. On the UE9, PIN2 and PIN20 are UART connections.

The table below shows the pinout of the DB37 connector on the LabJack.  Pins 1, 8, 10, 19, and 30, are all connected to GND on the LabJack.  On the CB37, all GND terminals connect to a single ground plane and this ground plane is connected to pins 1, 8, 10, and 19, of the DB37 connector.  The AGND terminal is simply connected to pin 30 of the DB37 connector.  That means the GND and AGND terminals connect to the same single ground plane on the LabJack, but they have different paths to get there.

Ground Offsets

When using the analog connections on the CB37, the effect of ground currents should be considered, particularly when a cable is used and substantial current is sourced/sunk through the CB37 terminals. For instance, a test was done with a 6 foot cable between the CB37 and a LabJack UE9, and a 100 ohm load placed from Vs to GND on the CB37 (~50 mA load). A measurement of CB37 GND compared to UE9 GND showed 5.9 mV. If a signal was connected to AIN0 on the CB37 and referred to GND on the CB37, the UE9 reading would be offset by 5.9 mV. The same test with the CB37 direct connected to the UE9 (no cable) resulted in an offset of only 0.2 mV. In both cases (cable or no cable), the voltage measured between CB37 AGND and UE9 GND was 0.0 mV.

Notes:
1.  6" Snap-Track not shown.

Common neutral format CAD models are provided below.  Right-click and select the "Save link as..." option to download STEP files. 

Datasheet Revision 1.03, 3/1/2007

The EB37 experiment board connects to the LabJack UE9’s DB37 connector and provides convenient screw terminal access. Also provided is a solderless breadboard and useful power supplies. The EB37 is designed to connect directly to the LabJack, but can also connect via a 37-line 1:1 male-female cable (not included).

The solderless breadboard is provided for convenient prototyping, and does not have any electrical connections to the rest of the EB37. Looking at the picture above, the breadboard has 2 long rows of 5*10=50 sockets at the top, and two more rows of 50 at the bottom. In each of these 4 rows, all 50 sockets are connected, and thus these rows are generally used as power rails. The remainder of the breadboard is filled with 126 columns of 5 connected sockets each. The breadboard is attached to the EB37 with adhesive. The breadboard area is about 6.5” (165 mm) by 2.2” (56 mm), so if a replacement is needed one possibility is the UBS-100 (available from mouser.com), which can be mounted using screws/nuts rather than adhesive. Note that the UBS-100 (and many similar breadboards) separates the power rails in the middle, such that there are 8 rows of 25 sockets.

The green LED on the EB37 is directly powered by the 5-volt supply (Vs) from the LabJack, so it should be lit whenever the EB37 is connected to a powered LabJack. The red LED is powered directly by the external power supply (wall-wart included).

The EB37 can be powered from the LabJack or the external supply. If both the LabJack and external supply are connected at the same time (both green and red LEDs on), the external supply will provide power. If the external supply is not connected (red LED off), then +/- 10 volts, 3.3 volts, 1.25 volts, and all Vs terminals are powered by the LabJack. If the external supply is connected (red LED on), then it provides power for +/- 10 volts, 3.3 volts, 1.25 volts, and all Vs terminals.

The LabJack always provides power for the green LED, VM+, VM-, and any current sourced/sunk by I/O lines, even if the wall-wart is connected.

In most cases the EB37 can simply be powered by the LabJack, but there are various reasons why powering from the external supply, rather than the LabJack, might be desirable. One obvious reason is if more power is required on the EB37 than can be provided by the LabJack. Other reasons could be avoiding a ground offset between the LabJack and EB37 (as discussed below), avoiding any degradation of the LabJack power supply, or providing an EB37 power supply that is on even when the LabJack is off.

Power Terminals

SGND: This terminal has a self-resetting thermal fuse (0.75 amps) in series with GND. Often used when connecting a ground from another powered system to create a common ground.

GND: All GND terminals are the same.

1.25V: Output from a 1.25 reference. The reference maintains 0.2% accuracy while sourcing up to 7 mA.

3.3V: Output from a 3.3 volt regulator. Provides up to 200 mA with 2% accuracy.

VS: All VS terminals are the same. These are outputs of the nominal 5 volt power supply provided by the LabJack or wall-wart.

+10V/-10V: Unregulated supply with a nominal output of 2*VS and –2*VS. This supply can provide up to 10 mA, but the output voltage decreases and output ripple increases with load.

When using the analog connections on the EB37, the effect of ground currents should be considered, particularly when a cable is used and substantial current is sourced/sunk through the EB37 terminals. For instance, a test was done with a 6 foot cable between the EB37 and a LabJack UE9, and a 100 ohm load placed from Vs to GND on the EB37 (~50 mA load). A measurement of EB37 GND compared to UE9 GND showed 5.9 mV. If a signal was connected to AIN0 on the EB37 and referred to GND on the EB37, the UE9 reading would be offset by 5.9 mV. The same test with the EB37 direct connected to the UE9 (no cable) resulted in an offset of only 0.2 mV. In both cases (cable or no cable), the voltage measured between EB37 AGND and UE9 GND was 0.0 mV.

When any sizeable cable lengths are involved, a good practice is to separate current carrying ground from ADC reference ground. One way to do this on the EB37 is to use GND as the current source/sink, and use AGND as the reference ground. This works well for passive sensors (no power supply), such as a thermocouple, where the only ground current is the return of the input bias current of the analog input. Another option is to use a separate ground wire for loads requiring substantial current.

Specifications:

(1) This is the current that must be provided by the LabJack or wall-wart just to power the EB37 with no connections. About 5 mA of this current is for the green or red LED. So if either the LabJack or wall-wart only is connected, it will be providing about 5.2 mA. If both are connected, the LabJack will only be providing 5 mA for the green LED, while the wall-wart will be providing 5.2 mA plus any extra load demands. Additionally, 1 mA of supply current is required for each 1 mA of load current on Vs, 1.25V, and 3.3V, and about 4 mA of supply current is required for each 1 mA of load current on +10V/-10V.

The EI-1022 is made by EIC.  It is a low cost temperature probe that is easy to use with any LabJack.

Description

The EI-1022 is a universal temperature probe that consists of a National Semiconductor temperature sensor mounted in a plastic tube with a current limiting resistor. This probe when connected to 5 volts DC will output a nominal 3.0 volts at room temperature. The probe is suitable for air and surface applications.

The EI-1022 is intended to be connected to a LabJack for 5 volt power but can be used as a stand alone temperature sensor when connected to a DVM and a 5 volt source.

Multiple probes can be connected to a single LabJack, up to the number of analog inputs available on the device.

Electrical Connections

Three wires require connections; they are +5 volts (red), ground (black) and output (white). These wires can be connected to the appropriate terminals on a LabJack or other power supply in the case of using the sensor as a stand-alone unit. The output wire will normally output a voltage of approximately 3 volts at room temperature.

LabJack U12 Quickstart

Connect the red wire to +5V, black wire to GND, and white wire to AI0.

Run LJlogger.  By default, the first row will be set to Channel = 0 SE, and the Voltage column should show something around 3.0 volts if the EI-1022 is at room temperature.

To improve resolution, you need to use gain which requires a differential channel.  Add a jumper wire from AI1 to GND, then in the desired row of LJlogger set Channel = 0-1 Diff.  Now you can adjust Gain so you are using the smallest range possible.  For example, the +/-4V range would allow temperatures up to 400 degrees K.

To make LJlogger display degrees C, enter 100.0 for multiplier and –273.15 for offset in the appropriate row.  To make LJlogger display degrees F, enter 180.0 for multiplier and –459.67 for offset. The scaled temperature will appear in the “Scaled Data” column.

UD Series and T Series Quickstart

Connect the red wire to VS, black wire to GND, and white wire to AIN0.

Run LJLogUD (UD series) or LJLogM (T series).  By default, the first row will be set to +Ch=0 and -Ch=199 (single-ended), and the Voltage column should show something around 3.0 volts if the EI-1022 is at room temperature.

U3 Comment:  If your max temperature will be less than 360 degrees K, you will get better resolution using a low-voltage channel (FIO or EIO) on the U3-HV, and that is the only option on the U3-LV.  Connect the white signal wire to FIO4 rather than AIN0. In LJLog set +Ch=4, and since the "Special 0-3.6" volt range is needed set -Ch=32.  In DAQFactory Express, put 32 in the QuickNote/Special/OPC column for a particular channel.

To make LJLog display degrees C, enter a scaling equation such as "y=100.0*c - 273.15" in the desired row.  Note that "c" in this example means it will use the voltage from the 3rd row, so use the appropriate variable from "a" to "p".  To make LJLog display degrees F, enter a scaling equation such as "y=180.0*c - 459.67" in the desired row.

Specifications

Range: -40°C to 100°C (-40°F to 212°F)

Output: 10 mV per °K absolute

Sensor device in probe: LM335A

Cable length: 6 ft supplied 500 ft user extended

Probe dimensions: 4 in x 0.25 diameter

Power: +5 VDC at .001 Amp

Output Load: 50K or greater or 100 µA max

Accuracy:

+/- 1°C Typical Room Temperature

+/- 3°C Max Room Temperature

+/- 2°C Typical -40°C to 100°C

+/- 5°C Max -40°C to 100°C

Formulas to Calculate Temperature From Measured Probe Voltage

°C = 100*volts – 273.15

°K = 100*volts

°F = ((100*volts)-273.15)*1.8 +32

Special Notice Regarding The EI-1022 Cable

Although the temperature sensor and associated electronics are rated for 100 degrees C, the cable is only rated for 80 degrees C. We have tested the cable, probe at 150 degrees C, and have noticed the cable gets soft at the high temperatures but continues to function. When the cable and probe were returned to normal temperatures, no degrading was observed in the cable or probe. Also at the low temperatures, the cable is only rated to -20 degrees C where the sensor and associated electronics are rated lower. Testing the probe with the wire at the lower temperatures showed normal operation and no degrading of the cable when returned to normal temperatures. The user should be aware that even though the probe itself can operate at the rated temperatures the use of the cable in environments of over 80 degrees C and lower than 20 degrees C is at your own risk.

Manufactured by:

ELECTRONIC INNOVATIONS CORP

Email: [email protected]

The EI-1034 is made by EIC.  It is temperature probe with excellent accuracy that is easy to use with any LabJack.

Description

The EI-1034 is a universal temperature probe that consists of a silicon type temperature sensor mounted in a waterproof 316 stainless steel tube.  It uses the LM34CAZ precision silicon temperature sensor with a typical room temperature accuracy of ±0.4 °F (±1.0 °F max). Because of the high-level linear voltage output and high accuracy, this probe is easier to use and superior to thermocouples, thermistors, or RTDs, for many applications in the range of 0 to 230 °F (temperature range varies with positive supply voltage, negative supply voltage, and LabJack model). The probe is suitable for air and liquid applications, and can be conveniently secured into pipes, vessels and chambers by using available ¼ inch compression fittings.

The EI-1034 is intended to be connected to a LabJack for 5-volt power but can be used as a stand-alone temperature sensor when connected to a DVM and a power supply in the range of 5 to 30 volts.

Electrical Connections

Three wires require connections; they are +5 volts (red), ground (black) and signal output (white). These wires can be connected to the appropriate terminal on the LabJack or other power supply in the case of using the sensor as a stand-alone unit. The output wire (white) connects to an analog input and will normally output a voltage of approximately 0.77 volts at room temperature.

Cable Length

The probe has a 10k internal resistor from signal to ground that helps keep the signal stable when sinking current or driving capacitive loads.  The cable length of the probe can be extended to 25 ft without serious degradation in performance. If the user desires to extend the length of the cable beyond 25 ft (up to 500 ft) then a resistor of 10K ohms should be inserted in series with the white wire. The resistor should be placed at the 6 ft length of the probe. When using a series resistor of 10K ohm the user should consider the voltage drop across the resistor when calculating the final temperature measurement.

Stream Mode

Temperature readings are not often acquired in high speed stream mode, but if they are note that the micropower drive circuit of the LM34 can be subject to settling errors in multiplexed applications.  Our testing on a T7 found that 50 μs of settling is required for the EI-1034.  Auto Settling can be as little as 10 on the T7, so you might need to write STREAM_SETTLING_US = 50.  Read more about settling time in the Analog Input Settling Time App Note.

Low Temperature Operation

The low temperature range of the EI-1034 can be extended to -40 °F by adding a 100K resistor to a negative supply voltage.  The Vm- supply on the U6 and T7 is handy for this.  Note that if you don't have a negative voltage available but do have an isolated voltage available such as a battery or wall-wart, you can connect it backwards to make a negative voltage. A standard wall plug-in supply can be used in the range of 5 to 15 volts. A 9-volt battery is also a good source for a negative voltage. Care must be taken to connect the positive terminal of the isolated supply to the GND wire (black) of the EI-1034 and the negative terminal of the supply in series with a 100K resistor to the white wire of the EI-1034.

Figure 1

Formulas to Calculate Temperature From Measured Probe Voltage

°F = 100*volts

°K = (55.56*volts) + 255.37

°C = (55.56*volts) + 255.37 - 273.15

LabJack U12 Quickstart

Connect the red wire to +5V, black wire to GND, and white wire to AI0.

Run LJlogger.  By default, the first row will be set to Channel = 0 SE, and the Voltage column should show something around 0.77 volts if the EI-1034 is at room temperature.

To improve resolution, you need to use gain which requires a differential channel.  Add a jumper wire from AI1 to GND, then in the desired row of LJlogger set Channel = 0-1 Diff.  Now you can adjust Gain so you are using the smallest range possible.  For example, the +/-2V range would allow temperatures up to 200 degrees F.

To make LJlogger display degrees C, enter 55.56 for multiplier and –17.78 for offset in the appropriate row.  To make LJlogger display degrees F, enter 100.0 for multiplier and 0.0 for offset. The scaled temperature will appear in the “Scaled Data” column.

U3/U6/UE9 Quickstart

Connect the red wire to VS, black wire to GND, and white wire to AIN0.

Run LJLogUD.  By default, the first row will be set to +Ch=0 and -Ch=199 (single-ended), and the Voltage column should show something around 0.77 volts if the EI-1034 is at room temperature.

To make LJLogUD display degrees C, enter a scaling equation such as "y=55.56*c - 17.78" in the desired row.  Note that "c" in this example means it will use the voltage from the 3rd row, so use the appropriate variable from "a" to "p".  To make LJLogUD display degrees F, enter a scaling equation such as "y=100.0*c" in the desired row.

U3 Comment:  You will get better resolution using a low-voltage channel (FIO or EIO) on the U3-HV, and that is the only option on the U3-LV.  Connect the white signal wire to FIO4 rather than AIN0, and in LJLogUD set +Ch=4 in any row.

T4/T7 Quickstart

Connect the red wire to VS, black wire to GND, and white wire to AIN0.  If the probe is at 70 degrees F, the voltage from AIN0 to GND should be 0.70 volts.

Traditional Technique:  Acquire the voltage and in software multiply it by 100 to convert to degrees F.

Run LJLogM.  By default, the first row will be set to AIN0, and the Voltage column should show something around 0.77 volts if the EI-1034 is at room temperature.

To make LJLogM display degrees C, enter a scaling equation such as "y=55.56*c - 17.78" in the desired row.  Note that "c" in this example means it will use the voltage from the 3rd row, so use the appropriate variable from "a" to "p".  To make LJLogM display degrees F, enter a scaling equation such as "y=100.0*c" in the desired row.

AIN-EF Technique:  Configure an extended feature on the applicable channel to apply a slope of 100, and then read AIN0_EF_READ_A to get the scaled value.

In Kipling, go to the Analog Inputs tab, click the "+" at the far right of the AIN0 row, set Extended Feature to "Slope/Offset", and set Slope=100.  Now you can read AIN0_EF_READ_A in any software, such as LJLogM, and get the scaled value.

T4 Comment:  You will get better resolution using a low-voltage channel (FIO or EIO) on the T4.  Connect the white signal wire to FIO4 rather than AIN0, and in LJLogM use "AIN4" in any row.

Specifications

Range with 0/5 volt supply:

+10 to +230 °F (-12 to +110 °C) with the LabJack U12

0 to +230 °F (-17 to +110 °C) for the LabJack U3 or UE9

Accuracy:

+/- 0.4°F Typical Room Temperature

+/- 1°F Max Room Temperature

+/- 2°F Max 0°F to 230°F

+/- 3°F Max -40°F to 0°F

Sensor device in probe: LM34CAZ

Cable length: 6 ft supplied max 25 ft user extended

Power: +4 to 35 VDC at 100-400 µA

Output Current: 10 mA

Note: When operating at voltages less than 5 Volts the maximum operating temperature is reduced, typically at 4 Volts supply the maximum temperature limit is 200 °F

Probe dimensions: 6 in x 0.25in diameter.  Metal tube is 316 stainless steel, product number SS-14-6CLOSED from Omega.

Possible fittings:
https://www.omega.com/en-us/sensors-and-sensing-equipment/sensing-accessories/connector-bushings-and-grommets/p/RA-RB
https://www.omega.com/en-us/pressure-measurement/pressure-measurement-accessories/pipe-and-tube-fittings/p/MTA-BRLK-SSLK-RA-RB-Series

More information:
LM34 Datasheet
Temperature Sensors Application Note

Special Notice Regarding The EI-1034 Cable

Although the temperature sensor and associated electronics are rated for 110 degrees C, the normal cable is only rated for 80 degrees C. We have tested the cable and probe at 150 degrees C, and have noticed the cable gets soft at the high temperatures but continues to function. When the cable and probe were returned to normal temperatures, no degrading was observed in the cable or probe. Also at the low temperatures, the cable is only rated to -20 degrees C where the sensor and associated electronics are rated lower. Testing the probe with the wire at the lower temperatures showed normal operation and no degrading of the cable when returned to normal temperatures. The user should be aware that even though the probe itself can operate at the rated temperatures the use of the cable in environments of over 80 degrees C and lower than 20 degrees C is at your own risk.

Manufactured by:

ELECTRONIC INNOVATIONS CORP

Email: [email protected]

End Of Life (EOL) Notice

Limited Availability:  The EI-1040 dual instrumentation amplifier, manufactured by Electronic Innovations Corporation and sold by LabJack, is at the end of production. Estimated time of NLA (no longer available) is Spring 2023.

Description

The EI-1040 is made by EIC.  It is a dual programmable gain instrumentation amplifier with a precision reference output for bridge excitation. Gains are digitally selected at values of 1, 10, 100, and 1000. Four TTL or CMOS- compatible address lines individually select the amplifier gains.

The EI-1040 is a common accessory for the LabJack U12.  For the U3 or UE9 the LJTick-InAmp is more commonly used.  The U6/T7 have an in-amp built-in, but if an external in-amp is needed the LJTick-InAmp is usually the best choice.

Applications of this device are for signal conditioning and amplification of low-level signals such as thermocouples and transducers. This device is also used in conditioning signals to be transmitted over a long distance to single ended receivers.

The EI-1040 requires +5 volts DC at a nominal 0.1 amp. An internal DC to DC converter supplies an output of +15 and –15 volts nominal. The EI-1040 consists of 2 Burr-Brown/TI PGA204 amplifiers and one DCP010515DPB DC to DC converter.

A 4.096 volt reference is provided for connection to a bridge or other device requiring excitation. The maximum allowable current draw from this source is 5 ma.

The EI-1040 can be attached to the LabJack by simply connecting the power and amplifier outputs to the LabJack. When connecting the EI-1040 to the LabJack, the LabJack should be powered down prior to making the connection. After the connection is made then the combination can be powered up.

The gain of the EI-1040 can be programmed by the LabJack by connecting the gain select inputs GSA1, GSA2, GSB1, and GSB2 to the LabJack digital outputs. The configuration for the gain select is shown below:

0 => -15 to +0.8 volts => GND In, GND, or a DIO set to output-low.
1 => +2 to +15 volts => +5V In, VS from LabJack, or a DIO set to output-high.

Example:  To set channel B to a gain of x100, you can jumper GSB1 to GND In and jumper GSB2 to +5V In.

It should be noted that when the EI-1040/LabJack is powered from limited power sources such as notebook computers, bus-powered hubs, etc., there may not be enough current to supply both devices. A message from the computer should tell the user of this condition.

A functional block diagram of the EI-1040 is shown below.

The following table describes the function of the EI-1040 terminals:

Table 1. EI - 1040 terminal information

* Worst case current availability - actual current availability may be greater
** Current availability is 3 mA max

The instrumentation amplifiers used are Texas Instruments/ Burr Brown PGA204 parts. The specifications for these parts can be obtained on Internet at:

http://www.ti.com/lit/ds/symlink/pga204.pdf

Typical applications for this unit include: SIGNAL CONDITIONER, THERMOCOUPLE AMPLIFIER, STRAIN GAUGE AMPLIFIER, DATA ACQUISITION APPLICATIONS, SIGNAL FILTER, AUDIO AMPLIFIER, MICROPHONE AMPLIFIER

For Technical Support Contact:

ELECTRONIC INNOVATIONS CORP

Email: [email protected]

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 6900 West Jefferson Ave Suite 110, Lakewood, CO 80235 USA
Declares that the product
Product Name: EI-1040
Model Number: EI1040
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements
EN 61000-4-2: 1995
EN 61000-4-3: 1995
and is marked with CE.

End Of Life (EOL) Notice

The EI-1050 from Electronic Innovations Corporation has been discontinued as Sensirion no longer makes the sensor used in the EI-1050.

Available alternatives are probes based on the SHT3X digital output sensor, such as the SHT35 which is more accurate than the SHT11 that was used in the EI-1050.  We might start selling a digital SHT3X probe at some point, but you can get probes using the SHT35 on Amazon right now:

https://smile.amazon.com/gp/product/B07RSYB6C4

https://smile.amazon.com/gp/product/B07ZGD8FKB

The SHT3X uses I2C, which is slightly different (i.e. not drop-in compatible) than the SBUS protocol used by the SHT11.  Available support:

•  LJM (T4, T7) - We can provide code examples right now, including Lua script.  This quarter we plan to add higher level support to LJM so these are as easy to use as the EI-1050.
•  UD (U3, U6, UE9) - We will likely be able to provide code examples on demand for most languages, but doubt that device firmware or the UD driver will be changed to provide higher level support than that.
•  U12 - No support for SHT3X, as the U12 does not support I2C.

Overview

The EI-1050 is made by EIC.  It is a digital relative humidity and temperature probe intended for use with any LabJack DAQ device. It combines a single chip sensor module with a selector chip and buffering components on a small PC board. The single chip sensor is manufactured by Sensirion and provides a 14-bit/12-bit (temperature/humidity) serial digital output for each reading. It is housed in a plastic tube (4.5 in by 0.625 in) with a 6 ft cable. The device includes two calibrated microsensors for relative humidity and temperature. Since the output is serial digital data, this results in superior signal quality, a fast response time and insensitivity to external disturbances (EMC). Each sensor is calibrated by Sensirion in a precision humidity chamber and the calibration coefficients are programmed into the OTP memory. These coefficients are used internally during measurements to calibrate the signals from the sensors. The interface to the EI-1050 is a 5-wire connection consisting of supply voltage, ground, clock, data, and enable. By using the enable line, multiple probes can be connected to a LabJack at once.

UD & LJM Device Connections

This section applies to all LabJack DAQ devices except the U12.

Supported UD-series devices:

• U3
• U6
• UE9

Supported T-series devices:

• T4
• T7

The EI-1050 uses an SHT11 digital sensor. A key specification of this sensor is that the signal input voltage for a logic-high is 80%-100% of the supply voltage.  80%-100% of a supply voltage of 5.0V is 4.0-5.0V, but all LabJacks (except the U12) have 3.3V logic—a digital output-high is 3.3V.  This is not a problem for the Data line, since to get a high on the serial bus the I/O line is set to input and the 22k pull-up brings the line above 4 volts, but the Clock line is driven output-high/output-low.  Thus for a direct digital output from the LabJack (U12 excepted) to provide the clock signal, the EI-1050 must be powered by 3.3V instead of 5.0V.

Red Wire (Power): Need to supply 3.3 volts. The simplest way to get 3.3 volts is by using a digital line configured as output-high. An analog output (DAC) can also be used. Note that a single FIO line can only provide enough power for up to 4 probes. An EIO/CIO/MIO line or DAC line can provide power for up to 20 probes.

Black Wire (Ground): Connect to any GND terminal.

Green Wire (Data): Any digital I/O line can be used.

White Wire (Clock): Any digital I/O line can be used.

Brown Wire (Enable): The probe is enabled when this line is pulled to the supply voltage (3.3 volts for UD-series and T-series devices). The probe is disabled when this line is pulled to ground. This allows multiple probes to be connected to a single device using the same Data and Clock lines, and only a unique Enable line is required for each probe.  (If only a single EI-1050 is being used, and you want it to be enabled all the time, the Enable line can be left unconnected because there is an internal pull-up resistor to the Power line. However, it's recommended to connect the Enable line to the same terminal as the Power line.)

If multiple probes are being used, they can all be connected to the same Power/Ground/Data/Clock terminals. The Enable line on each probe is connected to a unique digital output, and all enables are set to output-low to disable all probes. To get measurements from a particular probe, the Enable line for that probe is set to output-high, readings are taken, and then the Enable line is set back to output-low.

UD Library Communication (U3/U6/UE9):

The LabJack UD driver for Windows (V2.48+) has special support for the EI-1050. There is 1 IOType and 4 special channels:

LJ_ioSHT_GET_READING 
LJ_chSHT_TEMP   // Used with IOType above. 
LJ_chSHT_RH   // Used with IOType above. 
LJ_chSHT_DATA_CHANNEL // Used with LJ_ioPUT_CONFIG. 
LJ_chSHT_CLOCK_CHANNEL // Used with LJ_ioPUT_CONFIG. 

The EI-1050 Sample page has examples. The following pseudocode demonstrates retrieving measurements from a single probe:

//Set FIO2 to output-high to provide power to the EI-1050.  
ePut (lngHandle, LJ_ioPUT_DIGITAL_BIT, 2, 1, 0);    //Red = Power = FIO2
 
//Specify the data and clock lines.  
ePut (lngHandle, LJ_ioPUT_CONFIG, LJ_chSHT_DATA_CHANNEL, 0, 0);    //Green = Data = FIO0
ePut (lngHandle, LJ_ioPUT_CONFIG, LJ_chSHT_CLOCK_CHANNEL, 1, 0);   //White = Clock = FIO1
 
//Now, an add/go/get block to execute multiple requests. 
//Request a temperature reading from the EI-1050. 
AddRequest (lngHandle, LJ_ioSHT_GET_READING, LJ_chSHT_TEMP, 0, 0, 0); 
 
//Request a humidity reading from the EI-1050. 
AddRequest (lngHandle, LJ_ioSHT_GET_READING, LJ_chSHT_RH, 0, 0, 0); 
 
//Execute the requests.  Will take about 0.5 seconds with a USB high-high 
//or Ethernet connection, and about 1.5 seconds with a normal USB connection. 
GoOne (lngHandle); 
 
//Get the temperature reading result. 
GetResult (lngHandle, LJ_ioSHT_GET_READING, LJ_chSHT_TEMP, &dblTemperatureKelvin); 
 
//Get the humidity reading result. 
GetResult (lngHandle, LJ_ioSHT_GET_READING, LJ_chSHT_RH, &dblHumidityPercent);

If using multiple probes, you would also have the following calls:

• Enable the desired probe before each reading
• Disable the desired probe after each reading

T Series Communication:

See the SBUS section in the T-series datasheet; the Examples section provides a basic walk-through.

U12 Connections & Communication

Multiple EI-1050 probes can be connected to a single LabJack U12. When using multiple probes, the data and clock line from every probe connect to the same LabJack terminals (IO0 and IO1). An individual connection is needed for the enable line on each probe. The enable line is pulled high inside the probe, so the probe is enabled when this line is disconnected (not recommended), connected to +5V, connected to an analog output set to 5.0 volts, connected to a digital input, or connected to a digital output set high. The probe is disabled when the enable line is connected to GND, connected to an analog output set to 0.0 volts, or connected to a digital output set low. This can be accomplished using IO2, IO3, AOx, or Dx, providing multiple enable line connections. The example programs provided by LabJack Corporation, toggle the digital lines between input and output-low to enable and disable the probe (analog outputs are toggled between 0.0 volts and 5.0 volts). When the probe is disabled, it is powered-up, but there is no communication.

There are two example applications available from LabJack Corporation to experiment with the EI-1050 probe(s): LJSHT.exe and LJSHTmulti.exe. These are installed as part of the normal U12 Legacy installation and can be found in the start menu along with LJlogger, LJtest, and others. LJSHT acquires temperature and humidity readings from 1 or 2 probes and displays the information on a chart. LJSHTmulti acquires readings from many probes and displays the current readings in a table.

LabJack U12 drivers V1.10 and later have 3 new functions for communicating with the EI-1050 (and SHT1X sensors in general):

• SHT1X: This is the only function most programmers will use, and retrieves a temperature and/or humidity reading.
• SHTComm: A general function that sends and receives up to 4 bytes to/from a SHT1X sensor. Allows access to advanced features of the sensors.
• SHTCRC: Used with SHTComm. Checks the validity of a returned CRC byte.

For more information on the drivers functions, see the “LabJack U12 User’s Guide”.

LabJack U12 firmware V1.10 (serial numbers 100012000 and higher, 03/2003) and later has new functions to perform the SHT1X communication at a hardware level, such that one call to the LabJack U12 will send/receive up to 4 bytes of data. When using such hardware communication, it takes about 230 ms to get a 14 bit temperature reading and about 75 ms to get a 12 bit humidity reading. The LabJack U12 is busy during this time and unavailable for other operations.

When the LabJack U12 driver detects a firmware version earlier than V1.10, it reverts to software communication mode, and takes about 2 seconds to get a temperature or humidity reading. The LabJack U12 is busy during this time and unavailable for other operations. Firmware upgrade requires the replacement of a chip (which is socketed, not soldered). Contact LabJack Corporation for more information.

Having trouble with your EI-1050? Try running The EI-1050 Sample App.

Low-Level Interface

This information is mostly for talking to the EI-1050 with something other than a LabJack.

The EI-1050 uses the SHT11 from Sensirion. The SHT11 speaks SBUS, which is similar to I2C but not exactly the same. Details are provided by Sensirion.

The EI-1050 adds small RC filters (R=47 & C=1nF) to the Data and Clock lines.

The EI-1050 adds a MAX4514 switch to the Data line. This switch is controlled by the Enable line on the EI-1050. The Enable line has a 22k pull-up to Power.

The EI-1050 adds a 22k pull-up (to Power) to the Data line, but this is behind the switch so only connected when the probe is enabled.

Testing has shown that at least 11 sensors can run successfully off of one data/clock pair when connected to a T7 over short cable runs. The testing configurations were as follows:

• T7 FW 1.0282
• DAC0 set to 3.3V for power
• FIO0 and FIO1 for data and clock lines
• Default clock settings
• Normal 6ft. cables

Changing the data and clock lines to use EIO/CIO/MIO lines or slowing the clock down might allow for more sensors to be used at once.

Long cable runs can cause problems with data acquisition. It has been observed that a 70ft. Ethernet cable extension between one sensor and a T7 device resulted in frequent errors and poor quality data/clock lines.

Specifications

Relative Humidity Sensor (RH)

Range: 0 to 100 % RH

Accuracy: ±3.5 %

Response Time: 4 s

Reproducibility: H % R ±0.1

Resolution: 0.03 % RH

Temperature Sensor

Range: -40°C to 120°C

Accuracy:

0.5°C @ 25°C

0.9°C from 0 to 40°C

Response Time: 20 s

Reproducibility: ±0.1 °C

Resolution: 0.01 °C

Operating Temperature: -40°C to 120°C

General Electrical

Supply Voltage Range: 2.4 to 5.5 V

Input Current During Measurement: 0.6 mA

Input Current Standby: 0.12 mA

Cable Interface (LabJack U12 Terminal):

• Power: Red (3.3 V for UD-series and T-series, 5V for U12)

• Ground: Black (GND)

• Data: Green (FIO0 or other for UD-series and T-series, IO0 for U12)

• Clock: White (FIO1 or other for UD-series and T-series, IO1 for U12)

• Enable: Brown

Tube Dimensions

5/8" Outside Diameter

4 1/2" Length

Detail Specifications

More detailed specifications can be found in the SHT11 Datasheet from Sensirion.

Special Notice Regarding EI-1050 Cable

Although the temperature sensor and associated electronics are rated for 150 degrees C, the cable is only rated for 80 degrees C. We have tested the cable, probe at 150 degrees C, and have noticed the cable gets soft at the high temperatures but continues to function. When the cable and probe were returned to normal temperatures, no degrading was observed in the cable or probe. Also, at the low temperatures, the cable is only rated to -20 degrees C where the sensor and associated electronics are rated lower. Testing the probe with the wire at the lower temperatures showed normal operation and no degrading of the cable when returned to normal temperatures. Be aware that even though the probe itself can operate at the rated temperatures, the use of the cable in environments of over 80 degrees C and lower than 20 degrees C is at your own risk.

Special Notice Regarding Environmental Contamination

The tube provides protection from fingers and large contaminants, but additional protection is recommended if your environment has the risk of smaller contaminants such as insects, dust, or rain.

Manufactured by

ELECTRONIC INNOVATIONS CORP

Email: [email protected]

IDCA-10

DC Brushed Motor Drive

Motor Control Technologies, LLC

www.mocontech.com

11/2010, Rev. 1.0

The IDCA-10 is an integrated servo control system designed specifically for DC brushed motors. MCT brings a unique solution to motor control with this innovative product. The IDCA-10 possesses a dedicated PID control loop, localizing control functions on the motor hardware. The IDCA-10 is designed with flexibility in mind and is easily configured for a number of different operating modes. Operating modes include open-loop speed control, closed-loop speed control, and closed loop position control.

Digital communication is made available via a configurable 4-wire SPI or 3-wire SMBus/I2C serial bus. An optional stand-alone mode allows the user to utilize a single analog input signal to control the IDCA-10 in place of the serial bus.

The IDCA-10 also incorporates two encoder channels to interface with shaft encoders common to many motor assemblies. Two external inputs allow easy integration with limit/proximity switches to implement motor stops or fixed-position motor deceleration.

The IDCA-10 is ready to use right out of the box. An anodized aluminum heat sink and enclosure may be used as a stand-alone base, or integrated into existing hardware. The IDCA-10 also provides a convenient +5V regulated output to power encoders or other electronic components.

Specifications:

(1) Inability to adequately dissipate heat from the drive unit will result in lower continuous current limit due to over temperature shutdown limits.
(2) H-bridge IC junction temperature.
(3) 500 mA loads are not to exceed 30s in duration.
(4) RBR value measured when the bridge junction temperature at 25 C.
(5) Motor winding resistances less than that noted for RMOT can result in excessive bridge currents during breaking, and can cause serious damage to the IDCA-10.
(6) This is an abridged version of the DCA-10 specification sheet. A complete specification sheet is located in the product manual.

The LJTick-CurrentShunt (LJTCS) is a signal-conditioning module designed to convert 2x 4-20 mA current loop signals into voltage signals that vary from 0.472-2.360 volts. The 4-pin design plugs into the standard AnalogInput/AnalogInput/GND/VS screw terminal block found on newer LabJacks such as the U3, U6, UE9, T4, and T7. The major advantages of the LJTCS, compared to using a simple load resistor, are ease of use, high common-mode range, and lower voltage drop on the 4-20 mA signal.

Figure 1: LJTick-CurrentShunt

Figure 2: LJTick-CurrentShunt With U3

The pins shown on the right side of the LJTCS (Figure 1) connect to the LabJack. The VS/GND pins power the LJTCS, while the OUTA/OUTB pins send the output voltage signal to analog inputs on the LabJack.

Note that 4-20 mA corresponds to 0.472 to 2.36 volts, and thus on the U3-HV and T4 the low-voltage analog inputs (FIO/EIO) will provide the better results than the high-voltage analog inputs (AIN0-AIN3).

Following are descriptions of the LJTCS screw-terminal connections:

SGND: This terminal connects to LabJack ground (GND), with a 750 mA self-resetting thermal fuse in series. Often, the 4-20 mA sensor has its own power supply, and that supply ground needs to be connected to LabJack ground to provide a common reference. SGND allows that to be done, but protects from the risk of the external power supply dumping excess ground current through the LabJack.

VS: This is the same 5 volt output as the VS terminals on the LabJack itself. This is an output terminal, not an input. It can be used to provide 5 volt (nominal) power as needed.

INA+/INA- (or INB+/INB-): The 4-20 mA current loop should be connected to INA+ and INA- such that the current flows into INA+ and out of INA-. Each channel has a 5.9 Ω measurement resistor (0805, 0.10%, 50ppm), and the voltage across that resistor is amplified by x20. So 4 mA gives about 0.472 volts and 20 mA gives about 2.36 volts.

Relationship between output voltage and input current:

I = V / (20 * 5.9) = V / 118

mA = 8.475 * volts

In addition to the 5.9 Ω shunt resistor, there is a self-resetting thermal fuse in series. The fuse is the MICROSMD005F-2 with a hold current of 50 mA and trip current of 150 mA. It has a typical resistance of 18 Ω (min=3.6 and max=50). It does not affect the measurement, but does affect how much voltage is dropped as the 4-20 mA signal passes through the LJTCS.

The common-mode input range of the LJTCS is -8 to +28 volts. That means that the voltage of each of the inputs must be within that range compared to LJTCS ground.

If the 4-20 mA signal does not have a common reference at all with the LJTCS, one needs to be made. One common way of doing this is by connecting ground from the sensor to SGND on the LJTCS. SGND has a fuse in series and then connects to normal GND. The fuse is a 750 mA self-resetting thermal fuse, and prevents other systems from using the LJTCS ground as their power ground.

The following figures show typical connections. Figures 3 & 4 show typical connections with a 3-wire sourcing type sensor. This type of sensor sources the 4-20 mA signal, which is then returned to sensor ground. The common-mode voltage of INA- is 0, while the common-mode voltage of INA+ is equal to the signal loading of the LJTCS (typically 0.48 volts @ 20 mA).

Figure 3: 3-Wire Sourcing Sensor

Figure 4: 3-Wire Sourcing Sensor w/ Ext. Supply

Figures 5 & 6 show typical connections with a 2-wire (loop-powered) sourcing type sensor. This type of sensor sources the 4-20 mA signal, which is then returned to sensor ground. The common-mode voltage of INA- is 0, while the common-mode voltage of INA+ is equal to the signal loading of the LJTCS.

Figure 5: 2-Wire Sourcing Sensor

Figure 6: 2-Wire Sourcing Sensor

Figures 7 & 8 show typical connections with sinking type sensors. This type of sensor sinks the 4-20 mA signal, and thus the common-mode voltage of INA+ is equal to the full supply voltage and the common-mode voltage of INA- is equal to the supply voltage minus the signal loading of the LJTCS.

Figure 7: 3-Wire Sinking Sensor

Figure 8: 2-Wire Sinking Sensor

Troubleshooting:

• Do basic tests of the applicable AIN channel without the LJTCS connected.  Connect a jumper wire from AINx to VS or GND, and make sure it reads ~5V or 0V as expected.  See the Test an AIN Channel app note for more.
• Note the discussion above about having a common reference.  When you are using external supplies (Figures 4, 6, 7 and 8), those supplies must be referred to LabJack GND.  If the supplies are not already referred (the DC output of an AC-DC supply is usually floating), make one connection from the common/negative of each power supply to SGND or GND on the LJTCS or LabJack.
• Use a DMM to measure the voltage of IN+ and IN- versus GND.  Both must be in the range of -8 to +28 volts versus GND.
• Use a DMM to measure the voltage difference of IN+ versus IN-.  The total input impedance of the LJTCS varies from 9 to 56 ohms, but the typical value is 24 ohms, and if you are putting 10 mA (for example) through 24 ohms you should measure a voltage difference of about 0.24 volts.
• Use a DMM to measure the voltage of OUT/AIN versus GND.  The output voltage should be 20*5.9*I, so if the current is 10 mA (for example) the output voltage should be about 1.18 volts.
• Put a DMM in series with the IN+ terminal to see what it reports for current.
• Remove the LJTCS from the LabJack and remove all I/O connections, then use a DMM to measure the resistance from IN+ to IN-.  The total input impedance of the LJTCS varies from 9 to 56 ohms, but the typical value at room temperature is 24 ohms.
• Rather than connecting your signal, do a basic test with a 1k resistor connecting VS to IN+ and a jumper from IN- to GND.  This should result in roughly 5 mA (VS/1000), and then you can do the above measurements with that known current.
• Too much noise?  First step is to isolate the source of the noise to the LabJack, LJTick-CurrentShunt, or the signal itself.  Do the above test with a resistor, but rather than VS (which might be noisy) use a battery (great) or DAC output (good to great depending on device) with an appropriate resistor to get a current around 5 mA.

Custom Ranges:

The current on each channel flows into IN+, then through a self-resetting thermal fuse (F2/F3, MICROSMD005F-2), then through the 5.9 ohm 0805 0.1% sense resistor (R2/R5), and then back out IN-.  The voltage across the sensor resistor is multiplied by 20 to provide the output signal.  Some considerations if modifying R2/R5 to provide a custom range:

• If you plan to measure over 50 mA, you will need to change or short out the fuse.  Note that without the fuse if a low impedance voltage source is connected directly across IN+ and IN- there is high risk of damage.
• The gain is provided by an AD8202.  R3/R6 is the location for an 0805 feedback resistor (used to increase gain) and is normally not installed which means the gain is x20.
• The AD8202 gain can be reduced using a resistor from A1/A2 to GND.  The LJTCS has a 1000 pF capacitor C2/C4 from A1/A2 to GND, so that can be replaced with an 0603 resistor to reduce gain.
• The typical output voltage of the AD8202 is about 0.02 to VS-0.2, so 0.02-4.80 volts if VS = 5.0.
• The max recommended current due to the size of the PCB traces is 1 amp.  This is a conservative limit and 1 amp is definitely no problem.
• The burden voltage your signal must drive is the sum of the voltage drop across the fuse (varies from 3.6 to 50 ohms), the sensor resistor, and the PCB traces (typically less than 0.02 ohms).

Specifications:

(1) The 4-20 mA signal passes through a sense resistor, and the voltage across that resistor is amplified to produce the output voltage signal. Thus the response of the LJTick-Current is 118 mV/mA.
(2) The total input impedance is the sum of the sense resistor and the thermal fuse resistance, and is typically 21-27 ohms at room temperature. The voltage dropped across this total impedance by the 4-20 mA signal is the loading.
(3) The voltage from IN+/IN- to GND must stay within the common-mode limits.

Dimensions:

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 3232 S Vance St STE 200, Lakewood, CO 80227 USA
Declares that the product
Product Name: LabJack Tick Current Shunt
Model Number: LJTCS
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements

The LJTick-DAC works with the T-series (T4/T7) and with any UD family device (U3/U6/UE9), except for the oldest U3 hardware revision 1.20 (U3A, pre 2007), as that U3 did not support I2C.  The LJTick-DAC does not work with the U12.

The LJTick-DAC connects to a digital I/O block (e.g. FIO6/FIO7), not to the DAC0/DAC1 terminals.

Figure 1: LJTick-DAC

Figure 2: LJTick-DAC With U3

The LJTick-DAC (LJTDAC) is an analog output expansion module. It provides a pair of 14-bit analog outputs with a range of ±10 volts. The 4-pin design plugs into any of the standard DIO/DIO/GND/VS screw terminal blocks on the LabJack, and thus up to 10 of these can be used per device to add 20 analog outputs.

The update rate of the LJTDAC is limited by the communication time between the host and the device. See Section 3.1 of the U3/U6/UE9 User’s Guide or data rates for T-Series devices for detailed information, but it generally takes about 1 ms to do an update via USB “high-high” or Ethernet, while it takes about 4 ms via other USB connections. Only 1 DAC channel can be updated per low-level communication. That means, for instance, that if updates are done at the 1 ms rate to build a 100 Hz sine wave, there will only be about 5 updates per half-cycle of the waveform and it will appear to be a smooth sine. With a 10 Hz sine wave, however, there will be about 50 updates per half-cycle and the waveform will appear much smoother.

The pins shown on the right side of the LJTDAC (Figure 1) connect to the LabJack. The VS/GND pins power the LJTDAC, while the DIOA/DIOB pins are used for digital communication (I2C) between the LJTDAC and LabJack. DIOA is the serial clock (SCL) and DIOB is the serial data (SDA). Following are descriptions of the screw-terminal connections:

GND: Connected directly to LabJack ground (GND).

VS: This is the same 5 volt output as the VS terminals on the LabJack itself. This is an output terminal, not an input. It can be used to provide 5 volt (nominal) power as needed.

DACA/DACB: Output of each 14-bit digital-to-analog converter.

Low-Level I2C Communication

The LJTDAC has a non-volatile 128-byte EEPROM (Microchip 24C01C) on the I2C bus with a 7-bit address of 0x50 (d80), and thus an 8-bit address byte of 0xA0 (d160). Bytes 0-63 are available to the user, while bytes 64-127 are reserved.

The slopes and offsets are stored in 64-bit fixed point format (signed 32.32, little endian, 2’s complement). The serial number is simply an unsigned 32-bit value where byte 96 is the LSB and byte 99 is the MSB.

The DAC (digital-to-analog converter) chip on the LJTDAC is the LTC2617 (linear.com) with a 7-bit address of 0x12 (d18), and thus an 8-bit address byte of 0x24 (d36). The data is justified to 16 bits, so a binary value of 0 (actually 0-3) results in minimum output (~-10.3 volts) and a binary value of 65535 (actually 65532-65535) results in maximum output (~10.4 volts).

For more information about low-level communication with the LJTDAC, see the I2C example in the VC6_LJUD archive or see the Linux example.

UD Communication

The LJTick-DAC works with any UD family device (U3/U6/UE9), except for U3 hardware revision 1.20 (U3A), as that U3 did not support I2C. It also does not work with the U12 (which is not a UD family device).

The LabJack UD driver for Windows (V2.76+) has special support for the LJTDAC. First, the following special channel is used with the put config IOType to specify where the LJTDAC is connected to the LabJack:

LJ_chTDAC_SCL_PIN_NUM  //Used with LJ_ioPUT_CONFIG.  The desired pin # is passed in the Value parameter.

Then there is one IOType used for all further communication with the LJTDAC. The value of the Channel parameter used with this IOType is always one of the following 7 special channels:

LJ_ioTDAC_COMMUNICATION  //Main IOType. 
 
LJ_chTDAC_SERIAL_NUMBER  //Read-only. 
LJ_chTDAC_READ_USER_MEM  //x1 is array of 64 bytes. 
LJ_chTDAC_WRITE_USER_MEM //x1 is array of 64 bytes. 
LJ_chTDAC_READ_CAL_CONSTANTS //x1 is array of 4 doubles. 
LJ_chTDAC_WRITE_CAL_CONSTANTS //x1 is array of 4 doubles. 
LJ_chTDAC_UPDATE_DACA  //Pass DAC voltage in Value parameter. 
LJ_chTDAC_UPDATE_DACB  //Pass DAC voltage in Value parameter. 

Note that the _CAL_CONSTANTS special channels above are floating point doubles.  The UD library converts to/from the fixed point format stored on the LJTick-DAC.

Typical operation consists of simply setting the pin number for SCL and then updating DAC channel A and/or B:

//Tell the driver that SCL is on FIO6.  The driver then assumes that SDA is on FIO7. 
//This is just setting a parameter in the driver, and not actually talking 
//to the hardware, and thus executes very fast. 
ePut(lngHandle, LJ_ioPUT_CONFIG, LJ_chTDAC_SCL_PIN_NUM,6,0); 
 
//Set DACA to 1.2 volts.  If the driver has not previously talked to an LJTDAC 
//on FIO6/FIO7, it will first retrieve and store the calibration constants.  The 
//low-level I2C command can only update 1 DAC channel at a time, so there 
//is no advantage to doing two updates within a single add-go-get block. 
ePut(lngHandle, LJ_ioTDAC_COMMUNICATION, LJ_chTDAC_UPDATE_DACA, 1.2, 0); 
 
//Set DACB to 2.3 volts. 
ePut(lngHandle, LJ_ioTDAC_COMMUNICATION, LJ_chTDAC_UPDATE_DACB, 2.3, 0); 

For more information about UD communication with the LJTDAC, see the LJTDAC example in the VC6_LJUD archive.

T-series (T4/T7) & LJM Communication

The T-series have special registers available for controlling the LJTick-DAC.

Updating an output through the LJM library is easy.  For example, the following line of code:

err = LJM_eWriteName(handle, "TDAC11", 7.5)

... sets the voltage on the DACB channel associated with DIO11 (aka EIO3).  That means DACA on the LJTick-DAC would be connected to DIO10 (aka EIO2).

MIO2 (DIO22) does not support the LJTick-DAC.

Specifications: (25 deg C, VS = 5 volts)

(1) The update time is similar to the numbers found in Section 3.1 of the U3/UE9 User's Guide. The time is typically about 1 ms over Ethernet or USB "high-high", and typically about 4 ms over USB "other".
(2) This is the current limit for both channels combined.  The first thing you notice as you get close to the current limit is that the minimum output voltage increases, and this effect will be worse if your VS supply voltage is low.  For example, at 10 mA, the minimum output is typically about -9.5 volts.

Drawings:

LJTickDAC Testing Utility

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 3232 S Vance St STE 200, Lakewood, CO 80227 USA
Declares that the product
Product Name: LabJack Tick DAC
Model Number: LJTick-DAC
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements

This application will allow you to configure and test LJTick-DACs attached to any UD family device (UE9, U3, or U6). While the actual cross platform Python script is contained in the LabJackPython package, we provide a stand-alone application for the convenience of our customers running Microsoft Windows.

If you get an error message that says something like “This application has failed to start because the application configuration is incorrect …”, try downloading this update for your machine:

https://www.microsoft.com/en-us/download/details.aspx?id=26368

The LJTick-DigitalOut5V (LJT-DO5V) converts a LabJack's 3.3V digital outputs to 5V digital outputs. This allows a LabJack device to control 5V relays or interface with 5V logic devices/sensors. Read more about controlling relays and connecting 5V signals in this app-note.

• Output only
• Source or sink 50mA or more
• Up to 800kHz
• Interfacing with 5V logic circuitry

Note: When the LabJack digital I/O is configured as an input, the DigitalOut5V accessory will output logic low.

Common Applications

• Controlling relays that require 5V logic signals.

Figure 1: LJTick-DigitalOut5V

Figure 2: LJTick-DigitalOut5V with U3-LV

Screw Terminal Descriptions

VS: This is the same 5 volt output as the VS terminals on the LabJack itself. This is an output terminal, not an input. It can be used to provide 5 volt (nominal) power as needed.

GND: Same as LabJack ground (GND).

DOA/DOB: These lines are the converted 5V logic lines.

LJTick-DigitalOut5V Hardware Block Diagram

Figure 3: LJTick-DigitalOut5V Hardware Block Diagram

LJTick-DigitalOut5V Schematic

Figure 4: LJTick-DigitalOut5V Schematic

The AND gate has Schmitt trigger inputs (i.e. hysteresis), which help avoid rapid toggling if a noisy signal slowly changes state.

The AND gate is powered by 3.3 volts from a regulator.  An input of 0 to 1.0 volts will cause the output of the AND gate to be 0 volts.  An input of 2.3 to VS (nominally 5.0) volts will cause the output of the AND gate to be 3.3 volts.

The output amp is powered by VS & GND, and is set up with a gain of x1.5.  Thus the 3.3 volt high output of the AND gate will result in a 5.0 volt output from the amp, assuming a light load and assuming that VS is at least 5.0 volts.

If the DIO connected to the tick's input is set to output-high, the tick's output will be high.  It the DIO is set to output-low, the tick's output will be low.  If the DIO is set to input, the tick's output will be low (due to the pull-down resistors on the inputs).  This last fact can be useful when the DIO is configured to go to output-low at power up, as there is usually a brief time where the line will be input before the configuration takes effect.

Specifications

(1) Short circuit current is 120 mA, but useable current varies with how close to rail you need to drive per Figure 13 of the AD8646 datasheet. Figure 13 applies to both rails and applies to sinking or sourcing.  For example, if driving high and sourcing 50 mA there will be a saturation voltage of about 400 mV so the output will be about 4.6V rather than 5.0V.
(2) This is the recommended maximum frequency of a square wave of 50% duty cycle if the required output signal needs to get to both 0V and 5V. Faster frequencies will result in the signal not reaching 0V.
(3) An output frequency of 1MHz with both voltage rails being met can be achieved by using a duty cycle of 45%. The output waveform will look like a triangle wave at this point with the specified rise and fall times.

For more specifications about the logic gates and Op Amp used in the LJTick-DigitalOut5V look at the following datasheets:

• Diodes Incorporated 74AHC1G00 datasheet
• Analog Devices AD8646 datasheet

LJTick-Divider

The LJTick-Divider (LJTD) is a signal-conditioning module designed to divide 2 single-ended channels of higher voltage analog signals down to 0-3.5 volt signals. The stock builds provide divisions of /4, /5, /10, and /25, and there is a -C custom option for user specified builds.  The use of large resistors and a precision op-amp buffer provide an input impedance of about 1 MΩ. By adding or replacing resistors, many other configurations are possible.

The 4-pin design plugs into the standard AIN/AIN/GND/VS screw terminal block found on all LabJacks except the original U12.  Note that the best performance on the U3 or T7 is achieved with low-voltage inputs (labeled FIO and EIO).

Figure 1: LJTick-Divider

Figure 2: LJTick-Divider With UE9

VINA/VINB: These screw terminals are for the 2 single-ended channels of input analog voltages.  Each voltage is multiplied by the fractional slope to provide a lower voltage to the LabJack.  Note that the outputs of the LJTD are limited to about 0-3.5 volts.

GND: Same as LabJack ground. VINA/VINB must be referred to this ground.

VREF: A 2.5 volt reference voltage output. Internally this reference is used for level shifting, but very little current is used, leaving substantial current available to the user if a very accurate 2.5 volt reference is needed.

Figure 3: Schematic For Each Channel

The above figure is a schematic for one channel of the LJTD, showing the standard factory installed values for UNI10V. The input/output relationship is described by the below equations, assuming the op-amp is in the default unity gain configuration.

General Equations for Figure 3:
Vout = Vin*Rpar/(R1+R2)  +  Rpar*Vref/R4
Slope = Rpar/(R1+R2)
Offset = Rpar*Vref/R4
Rpar = Rparallel = 1 / ( (1/(R1+R2) + 1/R3 + 1/R4) )

Simplified Equations for Unipolar Builds:
Vout = Vin*R3/(R1+R2+R3)
Slope = R3/(R1+R2+R3)

The resistors R1+R2, R3, and R4, can be changed to provide other ranges as shown in the table below.

The packages for resistors R1-R4 are 0805, while all other resistors and capacitors are 0603. The tolerance of the factory installed resistors is 0.05%, so a good option available from digikey.com is the Panasonic ERA-6ARW series.

The table shows the input voltage at an output voltage of 0.0 and 2.5 volts. It also shows the input voltage for an output voltage of 3.5 volts, as the internal buffer amplifier accepts a maximum input voltage of 3.5 volts when powered by VS=5.0 volts, and thus when the amp is configured for unity gain the maximum output voltage is 3.5 volts. The Slope and Offset columns go with the formula

VIN (OUT=0):  This is the input voltage that results in an output voltage of 0.0 volts.  The typical minimum output voltage of the LJTD is about 0.001 volts.

VIN (OUT=2.5):  This is the input voltage that results in an output voltage of 2.5 volts.

VIN (OUT=3.5):  This is the input voltage that results in an output voltage of 3.5 volts.  The typical maximum output voltage of the LJTD is VS-1.5 which is about 3.5 volts.

Vout = Slope*Vin + Offset.

Table 1. Ranges for divider circuit with different R1-R4

The labels in the Name column are used when ordering custom configurations.

U3: The LJTD is generally used with low-voltage channels on the U3-LV or U3-HV.  The nominal input range of a low-voltage channel is 0-2.44 volts, so the input range provided by the LJTD is from the "VIN (OUT=0)" column to a little less than the "VIN (OUT=2.5)" column.  For example, the UNI10V in this case will provide an input range of about 0 to 9.76 volts.  If you set the U3 analog input to the "special" range it takes an input of about 0-3.6 volts, so the input range provided by the LJTD is from the "VIN (OUT=0)" column to the "VIN (OUT=3.5)" column.  For example, the UNI10V in this case will provide an input range of about 0 to 14 volts.

U6/T7: The LJTD is used with the +/-10 or +/-1 volt range on the LabJack U6/T7.  With the +/-10 volt range the full 0-3.5 volt output of the LJTD can be measured, but only 3.5/20 = 17.5% of the LabJack input range is used.  With the +/-1 volt range, the 0 and 1 volt output columns above apply, and 50% of the LabJack input range is used.

UE9: The LJTD is used withe the 0-2.5 or 0-5 volt range on the UE9.  The 0 and 2.5 volt output columns above use 100% of the 0-2.5 volt UE9 input range, or the 0 and 3.5 volt columns use 70% of the 0-5 volt UE9 input range.

Attenuating Higher Voltages

Due to the small trace spacing on the PCB, voltages beyond the options shown in the table above are not recommended.  Instead, higher voltages can be handled by adding 1 or more external resistors in series with VIN.  The extra voltage will be dropped across the external resistance such that the voltage applied to VIN is within specifications:

Simplified Equations for Unipolar Builds with External Resistor:
Vout = Vin*R3/(R1+R2+R3+Rext)
Slope = R3/(R1+R2+R3+Rext)

For example, say a 10 MΩ resistor such as the USF340-10.0M-0.01%-5PPM is used for Rext with the LJTick-Divider-25.  That means the slope will be 36.5k / (876k + 36.5k + 10000k) =  0.003345, and thus a voltage of 747 volts will be divided down to 2.5 volts.

When working with a high voltage system and a USB device, consider adding a USB isolator.  A mistake might damage the LabJack, but hopefully the isolator will protect the host computer.

Caution:  The information in this section (Attenuating Higher Voltages) is presented for convenience, is not a feature of normal LabJack operation, and you are at your own risk when working with high voltages.  High voltages are dangerous and only qualified individuals should work with high voltages.  A mistake could easily result in damage to the LabJack, computer, and people.

Using with Digital Signals

The LJTD can be plugged in to a digital I/O block and used to condition digital signals.  There are a couple reasons you might do this:

• Higher Voltages:  The LJTD-5 is perfect for handling 24 V signals.  24 divided by 5 is 4.8 volts, but the max output of the LJTD is about 3.5 volts, so the LabJack will see a 3.5 volt signal when the digital signal is driving 24 volts.  The LJTD-4 works for 12V or 24V logic.  A 12V signal will divide down to about 3.0V which is a logic high for any LabJack.  A 24V signal will result in about 3.5V, as that is the max output of the LJTD, and that also is a good logic high for any LabJack.
• Pull-Down Behavior:  From the schematic in Figure 3 above, you can see that RA3 acts as a pull-down resistor.  If the input (VIN) is disconnected or otherwise floating, the output of a unipolar LJTD will be near 0 volts.

Specifications:

(1) The maximum input voltage to the buffer amplifier is VS-1.5, so for proper operation with signals up to 2.5 volts, VS must be greater than 4.0 volts.

(2) The input impedance and bias current is dominated by the input resistors not the buffer amplifier. The input bias current of the internal buffer amplifier is less than ±200 pA across the voltage range, which is an important number as far as sizing the input resistors to not create excessive offset.

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 3232 S Vance St STE 200, Lakewood, CO 80227, USA
Declares that the product
Product Name: LJTick-Divider
Model Number: LJTD
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements

 LJ Tick-InAmp Datasheet Overview

The LJTick-InAmp (LJTIA) is a signal-conditioning module that provides two instrumentation amplifiers ideal for low-level signals such as bridge circuits (strain gauges) and thermocouples. The LJTIA has 5 gain settings per channel and two selectable output voltage offsets (Voffset). The 4-pin design plugs into the standard AIN/AIN/GND/VS screw-terminal block found on LabJacks such as the U3 and UE9.

The pictures below show the LJTIA plugged into the U3 on the left and plugged into the UE9 on the right.

Figure 1: LJTick-InAmp (LJTIA)

Figure 2: LJTIA With U3

Figure 3: LJTIA With UE9

The block of 4 screw-terminals at the left edge of the LJTIA (Figure 1 above) provides a positive and negative input for each differential channel. Towards the LabJack side of the LJTIA is a pair of screw-terminals that provide a ground connection (GND) and a +2.50 volt reference (VREF). The reference is capable of sourcing enough current (see Specifications) to function as the excitation voltage for most common bridge circuits.

In between the blocks of screw-terminals is a 10-position DIP switch used to specify gain and offset.

Table 1. DIP Switch Descriptions

Each channel has a switch (numbers 1 & 7) that has been left without factory-installed gain resistors:  R17 for channel A and R32 for channel B.  Resistors can be installed by the end-user to provide custom gains according to G=1+(100k/R). For example, a resistance of 100 ohms would provide the maximum allowable gain of 1001.  Also, multiple switches can be closed at the same time to get a few other gains (x61, x211, x251, and x261), as the gain settings resistors (10k, 2k, and 500) wind up in parallel. The packages for resistors R17 & R32 are 0805, while all other resistors and capacitors are 0603. The tolerance of the factory installed resistors is 0.1% & 25 ppm/degC, so consider the RG20P series from digikey.com (100ohm = RG20P100BCT).

Extending from the back of the LJTick-InAmp are four pins. The first two pins provide +5 volt power and ground from the LabJack. The other two pins are the instrumentation amplifier outputs and connect to analog inputs on the LabJack. The four pins plug directly into the 5.0 mm spaced screw-terminals on the LabJack U3, UE9, or other future devices as shown in Figure 4.

Figure 4: LJTick-InAmp lined up to UE9

Each channel on the LJTIA has an AD623 instrumentation amplifier (in-amp) from Analog Devices. The allowable signal range (Vin) is determined by a combination of Gain, Voffset, Vcm, and Vout. See the Signal Range Tables in Appendix A.

Voffset: This is an offset voltage added to the in-amp output. If DIP switch #5 is on, the offset is +0.4 volts, and if DIP switch #6 is on, the offset is +1.25 volts. The same offset applies to both channels of the LJTick-InAmp. One offset must always be selected (0 volts is not an option), but both offsets should never be enabled at the same time. The +0.4 volt offset is generally used with signals that are mostly unipolar, while the +1.25 volt offset is generally used with bipolar signals.

Vcm: This is the common mode voltage of the differential inputs. For an in-amp, that is defined as the average of the common mode voltage of each input. For instance, if the negative input is grounded, and single-ended signal is connected to the positive input, Vcm is equal to Vin/2. Another common situation is when using a wheatstone bridge where VREF=2.5 is providing the excitation. In this case, each input is at about 1.25 volts compared to ground, and thus Vcm is about 1.25 volts.

Vin: This is the voltage difference between IN+ and IN-. In the following Signal Range Tables, the “Low” column is the minimum Vin where Vout is 10 mV or higher, the “High 2.5V” column is the maximum Vin where Vout is 2.5 volts or less, and the “High 4.5V” column is the maximum Vin where Vout is 4.5 volts or less.

Vout: Vout = (Vin * Gain) + Voffset.  This is the single-ended (referred to ground) voltage output from the in-amp. Because of the power supply to the in-amp, the full output swing is about 0.01 volts to 4.5 volts. The “Low” and “High” columns in the Signal Range Tables give the output at the respective Vin.

Specifications

(1) The max accuracy specs are the tested device limits and are expected to be met whether device is warmed up or not.  Typical specs are what is normally seen with a warmed up device at room temperature. Gain and offset are very stable at a stable temperature, so a user-calibration can achieve accuracy much better than the specs listed here.
(2) The input signal limits are the simple limit of the voltage on each input terminal versus ground.  The output signal limit is the simple typical limit of the voltage that can be produced on the output pins, and depends on load so see the AD623 datasheet for more information.  The actual limits in most situations are more complex, as described in Appendix A of this datasheet.
(3) The current in/out of the input terminals is nanoamps from -0.3 to +5.3 volts.  Beyond that range it increases up to 10mA at -10 or +15 volts.
(4) This is the limit of the voltage on any input terminal versus ground.  See Appendix A for actual limits in different situations.
(5) Higher currents will not cause damage, but the reference voltage will start to sag. The reference output can handle a continuous short-circuit to ground and has a short-circuit current of about 45 mA typically.

Dimensions

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 3232 S Vance St STE 200, Lakewood, CO 80227 USA
Declares that the product
Product Name: LJTick-InAmp
Model Number: LJTIA
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements

The LJTick-InBuff (LJTIB) is an input buffer tick that allows LabJack devices to directly measure pH sensors and other kinds of weak signals. Our main LabJack DAQ products (U3, U6, UE9, and T7) require somewhere on the order of 10 to 100pA of bias current. This accessory can really help users trying to measure signals with >10MΩ of source impedance. The LJTick-InBuff accomplishes this by adding a Texas Instruments OPA2140 high-precision, low-noise Op Amp in between a devices analog input channel and the sensor. Simply connect the LJTick-InBuff to a screw terminal with analog inputs and connect a sensor to the INA or INB screw terminal of the LJTick-InBuff.

• 1pA bias current
• ±10V input & output range
• Has pads to optionally install gain resistors & input filter.

Common Applications

• Measuring PH sensors.

Figure 1: LJTick-InBuff

Figure 2: LJTick-InBuff with U3-LV

Screw Terminal Descriptions

VS: This is the same 5 volt output as the VS terminals on the LabJack itself. This is an output terminal, not an input. It can be used to provide 5 volt (nominal) power as needed.

GND: Same as LabJack ground (GND).

INA/INB: These input lines go through the Op Amps to have their signals amplified before being sent to a LabJack device.

LJTick-InBuff Hardware Block Diagram

Figure 3: LJTick-InBuff Schematic

LJTick-InBuff Schematic

Figure 4: LJTick-InBuff Schematic

Usage with the T4 or U3-HV

The T4 and U3-HV have a mix of high voltage analog inputs (±10 volt range) and low voltage analog inputs (±2.5/2.4 volt range).  Most input ticks are best used with the low voltage analog inputs, but the LJTick-InBuff is unique in that it has a ±10 volt output range and thus either type of analog input might be best depending on the range of the input signal.

Specifications:

For more specifications about the Op Amp used in the LJTick-InBuff refer to the Texas Instruments OPA2140 datasheet.

LJTick-LVDigitalIO Overview

The LJTick-LVDigitalIO (LJT-LVDIO) A bidirectional logic shifting board for converting 3.3V logic down to 2.5V or 1.8V. There is also a VOUT terminal which can source power at the selected voltage. Useful for users who have external boards that run on lower logic thresholds, or simply want a 3.3V, 2.5V, or 1.8V supply.

• Supports bi-directional communication
• Up to 800kHz
• 3.3V, 2.5V, or 1.8V
• VOUT terminal can source up to 200mA

Note: Advanced users may convert the 1.8V option to 5V by installing a jumper on R5, and removing or destroying the voltage regulator marked U3. Instructions for doing this can be found on the modifying the LJTick-LVDigitalIO page.

Common Applications

• Communicating with SPI, I2C, UART, 1-Wire, and other Digital IO sensors that require a supply voltage that is the same voltage as the logic level.

Figure 1: LJTick-LVDigitalIO

Figure 2: LJTick-LVDigitalIO with U3-LV

Screw Terminal Descriptions

Vout: This voltage can be selected to be either 3.3V, 2.5V, or 1.8V with the slide switch.

GND: Same as LabJack ground (GND).

DIOA/DIOB: These logic input and output lines can be configured to communicate with 3.3V, 2.5V, or 1.8V circuitry.

LJTick-LVDigitalIO Hardware Block Diagram

Figure 3: LJTick-LVDigitalIO Hardware Block Diagram

LJTick-LVDigitalIO Schematic

Figure 4: LJTick-LVDigitalIO Schematic

Specifications:

(1) Frequencies higher than 350kHz will not produce the full logic high voltage.

For more specifications about the MOSFETs and voltage regulators used in the LJTick-LVDigitalIO look at the following datasheets:

• ON Semiconductor (Logic Level Shifters) NTR4003N datasheet.
• Diodes Incorporated (3.3V Regulator) AP2127K-3.3TRG1 datasheet
• Richtek (2.5V Regulator) RT9193 datasheet
• Diodes Incorporated (1.8V Regulator) AP2127K-1.8TRG1 datasheet

The LJTick-OutBuff (LJTOB) is an output buffer tick that increases the output current of the DAC outputs on LabJack devices. The LJTick-OutBuff can also be used to increase the output abilities of the devices digital I/O lines by switching 3.3V logic. LabJack devices cannot output more than about 15mA on their DAC0 and DAC1 analog outputs so this accessory is helpful for users who want to increase that capability. One common application is to control the speed of a low voltage DC motor.

• Drives up to 200mA
• 0-5V output range*

* Max voltage depends on the supplied VS line which is 5V nominally.

Common Applications

• Controlling LEDs
• Generating variable stable excitation voltages

Figure 1: LJTick-OutBuff

Figure 2: LJTick-OutBuff with U3-LV

Screw Terminal Descriptions

VS: This is the same 5 volt output as the VS terminals on the LabJack itself. This is an output terminal, not an input. It can be used to provide 5 volt (nominal) power as needed.

GND: Same as LabJack ground (GND).

OBA/OBB: These output lines are generated by the Op Amp and track the input voltage.

LJTick-OutBuff Hardware Block Diagram

Figure 3: LJTick-OutBuff Hardware Block Diagram

LJTick-OutBuff Hardware Block Diagram with Filter

Figure 3: LJTick-OutBuff Hardware Block Diagram with Filter

LJTick-OutBuff Schematic

Figure 3: LJTick-OutBuff Schematic

Specifications

(1) Calculated by passing a 0-5V sine wave and measuring the input/output to get a -3dB difference.
(2) Capacitive loads beyond 1 nF might cause the output to oscillate. Add a 20 Ω series resistor to prevent this.

For more specifications about the Op Amp used in the LJTick-OutBuff refer to the Texas Instruments TLV4112 datasheet.

Datasheet Revision 1.00, June 4, 2007

The LJTick-Proto (LJTP) consists of an 8x8 grid of holes for prototyping custom signal-conditioning ticks. The 4-pin design plugs into the standard IO/IO/GND/VS screw terminal block found on newer LabJacks such as the U3, U6, and UE9. Includes 3 loose pieces: the PCB, a 4-position screw terminal, and a right-angle pin header.

Figure 1: LJTick-Proto (LJTP)

Besides the exceptions that follow, the LJTP consists of various unconnected holes. The user must provide the desired connections.

Towards the bottom left of Figure 1 is the large VS hole. When the right-angle pin header is installed and used to plug the LJTP into a LabJack, this point will be VS. There are six small holes which are connected to the large VS hole. Two holes on the LabJack side of the 8x8 grid (towards bottom of Figure 1) and four holes on the other side of the 8x8 grid (towards top of Figure 1).

Towards the bottom left of Figure 1 is the large GND hole. This GND hole is connected to the ground plane throughout the LJTP. There are 9 additional small holes at the other end of the LJTP which are also connected to ground.

Besides the GND and VS holes, no other holes are connected to anything.

The 8x8 grid of holes is surrounded on the top side by a plane connected to ground. This makes it easy to connect any of these holes to ground with a little blob of solder.

Figures 2 and 3 show an example build-up of an LJTP. In this case the LJTP has been used to assemble a 2X output amplifier designed to convert 0-5 volt analog outputs to 0-10 volts. This uses the LT1490 op-amp to make a pair of non-inverting amplifier circuits with a gain of ~2. The terminal labeled “+10V” is used to provide a >10 volt supply to power the op-amp.

Figure 3 also shows the various surface mount pads available on the LJTP. None of the pads are connected to anything.

The 4-position screw terminal is a Phoenix 1729034 or similar.  The right-angle pin header is a Samtec FWS-04-02-T-S-RA.  Any connector designed for 5 mm or 0.2" hole-spacing should be fine.

Figure 2: 2X output amplifier built on LJTick-Proto (Top)

Figure 3: 2X output amplifier built on LJTick-Proto (Bottom)

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 3232 S Vance St STE 200, Lakewood, CO 80227, USA
Declares that the product
Product Name: LabJack Tick Proto
Model Number: LJTP
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements

The LJTick-RelayDriver (LJTRD) is a signal-conditioning module that allows two digital outputs to each control up to 50 volts and 200 mA. The 4-pin design plugs into the standard DIO/DIO/GND/VS screw terminal block found on newer LabJacks such as the U3 and UE9.

In a scenario requiring multiple LJTick-RelayDrivers, consider instead the PS12DC power switching board.  It operates in a similar way, but has 12 channels, high side switching, and digital isolation. 

The pictures below show the LJTRD by itself and plugged in to a LabJack.

Figure 1: LJTick-RelayDriver (LJTRD)

Figure 2: LJTRD With U3

Extending from the back of the LJTRD are four pins. The first two pins provide +5 volt power and ground from the LabJack, although +5 volt power is not used by the LJTRD and thus is not connected to anything. The other two pins connect to digital I/O on the LabJack. The four pins plug directly into the 5.0 mm spaced screw terminals on the LabJack U3/UE9 as shown in Figure 2. The LJTRD should be plugged into a digital I/O block, as opposed to an analog I/O block.

The LJTRD has a 4-position screw-terminal providing the following connections:

RA/RB: The high side of each output switch. When IOA/IOB from the LabJack is set to output-high, the respective switch is closed. When IOA/IOB is set to output-low or input, the respective switch is open. Each switch can hold off up to 50 volts and can sink up to 200 mA.

GNDR: The low side of both output switches. Connected to LabJack GND via a 22 ohm resistor (resistor is on the LJRTD).

VR: Connect the load voltage to this terminal to bias the internal clamping diodes on each switch. If each switch has a different load voltage, the highest voltage should be connected to VR. The clamping diodes help suppress switching transients, and can be particularly important when dealing with inductive loads such as mechanical relays or solenoids. Although this connection is optional, there is usually no reason not to use it.

When connecting a relay or other type of load, there will be a voltage drop depending on current. Below is a chart which represents the voltage drops that can be expected at various currents.

Table 3. Voltage drop based on current

If controlling at high frequencies, please note the following table.  As current through the RelayDriver increases, the cutoff frequency also increases, which means that if you encounter problems controlling at high frequencies, the load resistance should be decreased to allow more current to flow through the RelayDriver.  This behavior is almost never a problem when controlling relays, since relays typically draw 3 to 20mA, and the LabJack U3 will not output a PWM frequency exceeding 187kHz.

Table 4. Cutoff Frequency based on current

The LJTRD uses the ULN2003AID high-current darlington transistor array.  See that datasheet for more details.

Following are two figures showing typical connections for the LJTRD. The first diagram shows the general connections, while the second is for the specific case where the LJTRD is controlling VS (5 volts) from the LabJack itself.

Figure 5: General Connection Diagram

Figure 6: Connection Diagram When Controlling VS from LabJack

Testing Basic Operation

Use the Dashboard in Kipling (T-series) or the Test panel in LJControlPanel to control the applicable DIO lines.  The DIO have 3 states (i.e. tristate digital I/O):

Output-High:  Active.  The "switch" on the LJTRD is closed.
Output-Low:  Disabled.  The "switch" on the LJTRD is open.
Input:  Disabled.  The "switch" on the LJTRD is open.

If the "switch" mentioned above was mechanical you could simply put a DMM from RA to GNDR and measure resistance, but that generally does not work with solid-state switches.  With a solid-state switch the best way to test is to connect as shown in Figure 6 but put in a resistor where it says "Relay Control".  So for example, connect one side of a 1k resistor (100 to 1,000,000 should work) to any VS terminal (~5 volts), connect the other side to RA, and connect GNDR to any GND terminal.  Now use your DMM to measure the voltage across the resistor.  When the LJTRD is disabled the voltage will be 0 as no current is flowing so no voltage is dropping.  When the LJTRD is active the voltage will be perhaps 3-5 volts (see Table 3 above).

Declaration of Conformity

Manufacturers Name: LabJack Corporation
Manufacturers Address: 3232 S Vance St STE 200, Lakewood, CO 80227 USA
Declares that the product
Product Name: LabJack Tick Relay Driver
Model Number: LJTRD
conforms to the following Product Specifications:
EMC Directive: 89/336/EEC
EN 55011 Class A
EN 61326-1: General Requirements

The LJTick-Resistance (LJTR) makes it easy for LabJack devices to measure resistive sensors. This tick gives users a regulated 2.5V signal that can be used as a excitation voltage and a known resistance value (1k, 10k, 100k, or 1M) to ground that forms a voltage divider with the unknown resistor.  Measuring the voltage output of the voltage divider allows the calculation of the unknown resistance value.

The LJTR connects to an analog input block on a U3, U6, UE9, or T-series LabJack DAQ device.  Thus it uses 2 analog inputs and measures 2 resistances.

Figure 1: LJTick-Resistance

Figure 2: LJTick-Resistance with U3-LV

Common Applications

The LJTR is designed to measure the value of an unknown resistance.  Some common examples are:

• Resistors
• Thermistors
• RTDs (PT100, PT1000, etc.)

Screw Terminal Descriptions

Vref: A 2.5 volt reference voltage output. Internally this reference is used for level shifting, but very little current is used, leaving substantial current available to the user if a very accurate 2.5 volt reference is needed.

GND: Same as LabJack ground (GND).

VINA/VINB: These are the LJTick-Resistance input terminals.

LJTick-Resistance Hardware Block Diagram

Figure 3: LJTick-Resistance Hardware Block Diagram

Note: The part labeled as the "Precision Resistor" is the 1k, 10k, 100k, or 1M precision resistor that varies between the LJTick-Resistance variants.

LJTick-Resistance Schematic

Figure 4: LJTick-Resistance Schematic

Note: The part labeled as the "Precision Resistor" is the 1k, 10k, 100k, or 1M precision resistor that varies between the LJTick-Resistance variants.

Equations

Typical wiring is to connect Vref to one side of the unknown resistance, and the other side of the unknown resistance to VIN.  This forms a voltage divider with the precision resistor to ground which we will call Rfixed.

The Vref on the LJTR is exceptionally accurate.  By specification it is more accurate than an analog input using the +/-10V range on even the U6-Pro and T7-Pro, so AIN feedback is generally not used but rather it is best to simply assume a constant of 2.500 V.

Vout = Vref*Rfixed/(Runknown+Rfixed)

Runknown = (Vref-Vout)*Rfixed/Vout

Runknown = (2.5-Vout)*10000/Vout    // LJTR-10k using the 2.5V reference

Example 1, PT100 RTD:  For a PT100 you expect that it will be 100.0 ohms at 0 °C and the resistance will change about 0.385 ohms/°C (most common coefficient).  Say room temperature is 22 °C and putting your fingers on the sensor warms it up to 25 °C.  At 22 °C you expect 108.47 ohms and at 25 °C you expect 109.63 ohms.  The voltages you expect are:

22 °C => 2.255361 V

25 °C => 2.253003 V

Example 2, PT1000 RTD:  For a PT1000 you expect that it will be 1000.0 ohms at 0 °C and the resistance will change about 3.85 ohms/°C (most common coefficient).  Say room temperature is 22 °C and putting your fingers on the sensor warms it up to 25 °C.  At 22 °C you expect 1084.7 ohms and at 25 °C you expect 1096.3 ohms.  The voltages you expect are:

22 °C => 1.199213 V

25 °C => 1.192577 V

See more information see forum topic #4257, which includes discussion of error due to lead-wire resistance and discussion of 3-wire and 4-wire resistance measurements.

Example 3, 10k Thermistor:  The LJTR relationship between voltage and resistance is given above.  To convert resistance to temperature we will use the Steinhart-Hart equation:

TempK = 1 / ( A + B*ln(R/R25) + C*ln(R/R25)^2 + D*ln(R/R25)^3 )

"R" is the actual thermistor resistance and "R25" is the nominal thermistor resistance at 25 degrees C.  The coefficients A, B, C, and D are needed, so for the NTCLE100E3103 thermistor (for example) the datasheet tells us A=0.003354016, B=0.000256985, C=0.000002620, and D=0.00000006383.

For more information about using these equations in LJLogUD or LJLogM, see the LJLog/Stream Scaling Equations page.

Note that on the T7 there you can use the AIN-EF system to do resistance, thermistor, and RTD math, but still the above is useful for understanding and troubleshooting.

Low-Pass Filter

All variations of the LJTR have C1=100pF installed.  This combines with Runknown to create a low-pass filter with a -3dB frequency as follows:

f = 1/(2*Pi*C1*(Ru+R1+R2))

Table 1. Cutoff frequency for C1=100pF with various source resistances.

The reason for the filter is that this type of resistance measurement application often leads to an input wire with very high source impedance which is therefore very susceptible to noise.  For example, say wire A connects Vref to a 1M resistor, and wire B connects the other side of the resistor to VIN.  Wire A is driven strongly by the low-source impedance Vref, and is not particularly susceptible to noise.  Wire B, however, has 1M of source impedance and thus is weakly driving VIN, and is quite susceptible to noise.  Capacitor C1 can help eliminate much of this noise.

Choosing the 1k, 10k, 100k, or 1M Version

A rule of thumb is to choose the version that most closely matches your typical resistance value, but to really get into details here is a spreadsheet that lists output voltage versus resistance for the different versions.  Save a copy of this to your Google Drive or local machine if you want to edit.

For example, say you have a 10k thermistor and want to measure a 0.1 °C change around the area of 20 °C.  From L73 we expect a resistance of 12260 ohms at 20.0 °C, and from F73 we know that we will get a change of about -490 ohms/degree round 20 °C, so at 20.1 °C we expect 12309 ohms.  We put those resistances in B46 & B47, and then look at the resulting Vout changes for the different LJTR variations in row 52.  We can see that the -10k variation gives the largest change at 2.467 mV and thus is a likely choice.

One other consideration, though, is that if we choose the -1k variation the voltages being measured are less than 1 volt so we can use the ±1 volt analog input range on the U6/T7 and get better resolution than on the ±10 volt range.  Similar logic can be used to keep readings below the limit of a low voltage analog input on the U3 (2.44V) and T4 (2.5V).

Resolution

To evaluate resolution we need to look at 3 steps:

1.  The thermistor or RTD has a varying resistance related to temperature.
2.  The LJTR converts varying resistance to varying voltage.
3.  The LabJack digitizes the varying voltage.

Thermistor Example:

1.  Let's say we plan to use a Vishay NTCLE100E3103 10k thermistor to measure from +20 to +150 °C.  Use a chart provided by the manufacturer (or use coefficients with an online calculator) to find the resistance at the ends of the range of interest:

http://www.vishay.com/docs/29049/ntcle100.pdf

°C      Ohms
15      15698
20      12488
145        205.5
150        182.6

We get the smallest change at the higher temperatures (only ~23 ohms), as expected with all NTC thermistors, so this is where we focus our further evaluation.  We will look at 145 °C and 150 °C where the resistance changes from 205.5 to 182.6 ohms.

 
2.  Use the LJTR equations from above, or a copy of our LJTR spreadsheet, to get the voltages.  That results in 2.4497 volts at 205.5 ohms, and 2.4552 volts at 182.6 ohms.  Thus a change of 0.0055 volts per 5 degrees, or 0.0011 volts/°C.

 
3.  The noise level of our 12-bit class devices is generally just 1 or 2 counts, so to get the voltage resolution just look at span divided by counts.  The input range of low voltage analog inputs (FIO/EIO) on the T4 is 0-2.5 volts, so voltage resolution is 2.5 / 2^12 = 0.0006 volts/count (U3 is about the same), which we combine with our 0.0011 volts/°C number from above to get:

(0.0011 volts/°C)  /  (0.0006 volts/count)    =    1.8 counts/°C  or 0.55 °C/count

So the resolution is about half a degree C when using this 10k thermistor with a U3/T4 to measure around 150 °C.  For improvement move to a higher resolution device such as the U6 or T7 families, and for these high resolution devices use the applicable appendix in their data sheet to determine voltage resolution for different configurations.  For example, from Table A.3.1.1 of the T-Series Datasheet, we see that the T7-Pro has an effective resolution of 0.0000057 V at Range=10 and ResolutionIndex=12 which equates to 0.005 °C.

RTD Example:

1.  Let's say we plan to use a PT100 that will be 100.0 ohms at 0 °C and has the standard response of 0.385 ohms/°C.  We are interested in room temperature so we look at 22 and 25 °C.

°C      Ohms
22      108.47
25      109.63

22 °C => 2.255361 V

25 °C => 2.253003 V

 
2.  Use the LJTR equations from above, or a copy of our LJTR spreadsheet, to get the voltages.  That results in 2.255361 volts at 108.47 ohms, and 2.253003 volts at 109.63 ohms.  Thus a change of 0.002358 volts per 3 degrees, or 0.000786 volts/°C.

 
3.  The noise level of our 12-bit class devices is generally just 1 or 2 counts, so to get the voltage resolution just look at span divided by counts.  The input range of low voltage analog inputs (FIO/EIO) on the T4 is 0-2.5 volts, so voltage resolution is 2.5 / 2^12 = 0.0006 volts/count (U3 is about the same), which we combine with our 0.000786 volts/°C number from above to get:

(0.000786 volts/°C)  /  (0.0006 volts/count)    =    1.3 counts/°C  or 0.76 °C/count

So the resolution is about 3/4 a degree C when using a PT100 with a U3/T4.  For improvement move to a higher resolution device such as the U6 or T7 families, and for these high resolution devices use the applicable appendix in their data sheet to determine voltage resolution for different configurations.  For example, from Table A.3.1.1 of the T-Series Datasheet, we see that the T7-Pro has an effective resolution of 0.0000057 V at Range=10 and ResolutionIndex=12 which equates to 0.007 °C.

Accuracy

Now we continue the above resolution discussion to move into the realm of accuracy.  As with most signals, the best accuracy is usually achieved with an in-situ calibration.  This means connecting everything up and then at different temperatures note the voltage reading from a particular channel and the actual temperature from some reference or known condition.  Then use that information in your software to equate further voltage readings to temperature.

Without an in-situ calibration, no calibration is applied and thus an error analysis needs to be performed on the entire system to come up with total error. Such an analysis is quite complex, but we can look at a list of error sources and see which appear important.  

1.  Accuracy of the thermistor or RTD itself in its conversion of temperature to resistance.  The datasheet for the Vishay NTCLE100E3103 10k thermistor says the R25 tolerance is ±2.0% (best grade) and the Beta tolerance is ±0.75%.

2.  Accuracy of the LJTR in its conversion of resistance to voltage.  One source of  error is the reference voltage accuracy of ±0.04%.  The other notable source of error is the tolerance of Rfixed which is ±0.05%.

3.  Accuracy of the LabJack in its digitization of the voltage.  For the T4 this is found in Table A.3-1 of the T-Series Datasheet and is 0.13% full-span.  For the T7 this is found in Table A.3-2 of the T-Series Datasheet and is 0.01% full-span.

4.  Voltage drop error due to current flowing in sensor wires.  If using a 2-wire connection the resistance of the lead wires could be noticeable.  With a thermistor this error only might be noticable at high temperatures where the thermistor resistance is smaller.  In our example in the Resolution section above the thermistor changes about 23 ohms from 145 °C to 150 °C, so 0.1 °C equates to about 0.5 ohms. Lead wires that are too skinny or too long could have a resistance of 0.5 ohms and thus cause 0.1 °C error. For example, 200 ft of 18 AWG wire has a resistance of about 1.28 ohms.  See related discussion in forum topic 4257.

In this list of errors, #1 is dominant for this thermistor and the other error sources are negligible.  Some RTDs have a much better accuracy rating and thus the other errors might be important.

Specifications:

(1) The maximum input voltage to the buffer amplifier is VS-1.5, so for proper operation with signals up to 2.5 volts, VS must be greater than 4.0 volts.

For more specifications about the reference voltage IC and Op Amp used in the LJTick-Resistance look at the following datasheets:

• Maxim MAX6070 datasheet
• Texas Instruments OPA2335 datasheet

The LJTick-VRef-25 (LJTVR-25) and LJTick-VRef-41 (LJTVR-41) are accessories that provide screw terminal access to stable 2.5V and 4.096V reference voltages. Reference voltages are useful when trying to communicate with several different sensors ranging from temperature, pressure, flow, motion, vibration, force, and more. The VS line on most of our devices is not suitable for direct control of sensors that require noise free voltage sources. Without a stable reference voltages many applications need to use a digital I/O line, one of the analog output channels, or use a secondary power supply. The LJTVR-25 and LJTVR-41 both have a LJT1461A voltage regulator on board to supply 50mA of current to sensors requiring excitation signals. The LJTick-VRef-25 outputs 2.5V and the LJTick-VRef-41 outputs 4.096V.

Common Applications

• Whenever a regulated 2.5V or 4.1V signal is needed.

LJTick-VRef-25 Images

Figure 1: LJTick-VRef-25

Figure 2: LJTick-VRef-25 with U3-LV

LJTick-VRef-25 Screw Terminal Descriptions

2.500: This screw terminal outputs the 2.5V reference voltage.

GND: Same as LabJack ground.

IOA/IOB: These lines are directly passed through from the screw terminals they are connected to. In Figure 2 they are FIO0 and FIO1.

LJTick-VRef-41 Images

Figure 3: LJTick-VRef-41

Figure 4: LJTick-VRef-41 with U3-LV

LJTick-VRef-41 Screw Terminal Descriptions

4.096: This screw terminal outputs the 4.096V reference voltage.

GND: Same as LabJack ground.

IOA/IOB: These lines are directly passed through from the screw terminals they are connected to. In Figure 4 they are FIO0 and FIO1.

LJTick-VRef Schematic

Figure 5: LJTick-VRef Schematic

Specifications:

(1) With a normal supply voltage of ≥ 4.75 volts, the device can meet specifications up to 50 mA.  At lower voltages the output current while meeting specs is limited by the Dropout Voltage spec from the LJ1461 datasheet.

For more specifications refer to the Linear Technology LT1416 datasheet. Both the LJTick-VRef-25 and LJTick-VRef-41 use the "C" variant. The VRef-25 uses the 2.5V variant and the VRef-41 uses the 4.096V variant.

Features

• 80 Multiplexed Channels (or 40 Differential Pairs)
• Built-In DC-DC Converter
• OEM Capability
• Easy-To-Use High Density Connectors
• Snaptrack/DIN-rail compatible, with TE Connectivity P/N TKAD

Connection Options

The Mux80 can be connected several ways.  The images below demonstrate use with the CB37 Terminal Board, and several 3ft DB37 Cables.

When connected to a CB37, there is a quick way to determine which screw terminals can be used as analog inputs; reference the chart printed on the top of the Mux80, also shown below for reference.

Table 1. CB37 to MUX80 connection chart

The above table defines the pinouts of X2-X5 in terms of a CB37.  If not using a CB37 see the CB37 Datasheet to translate the CB37 terminals to DB37 pin numbers.

X2

Connector X2 is essentially a duplicate of the DB37 connector on the main device, except AIN4-AIN11 are instead AIN120-AIN127, and AIN12-AIN13 are not connected to anything. On connector X2, AIN0-AIN3 are duplicates of the main device, as well as FIO, DAC, etc.

AIN0-AIN3 are available on the built-in terminals of the T7 and also on AIN0-AIN3 of a CB37 connected to X2.

AIN120-AIN127 are available on X2, along with the DACs and DIO.

X3

AIN48-AIN71 appear on the AIN0 through FIO7 terminals of a CB37 connected to X3.  Note that terminals labeled DACx and FIOx on the CB37 are used as analog inputs.

X4

AIN72-AIN95 appear on the AIN0 through FIO7 terminals of a CB37 connected to X4.  Note that terminals labeled DACx and FIOx on the CB37 are used as analog inputs.

X5

AIN96-AIN119 appear on the AIN0 through FIO7 terminals of a CB37 connected to X5.  Note that terminals labeled DACx and FIOx on the CB37 are used as analog inputs.

Example

A signal is connected to FIO6 on a CB37.  The CB37 is connected to X4 on the Mux80, so on the chart, under X4 and FIO0-7, locate AIN88-95.  So the signal is connected to AIN94.  To read AIN94 simply perform a standard AIN read for analog input number 94.

Using Differential Analog Inputs with the MUX80

Built-in

The built-in analog inputs AIN0 through AIN3 can be used normally when using the Mux80 (but AIN4 through AIN13 are not available). This allows:

• Positive channel = AIN0 paired with negative channel = AIN1
• Positive channel = AIN2 paired with negative channel = AIN3

See 14.0 AIN of the T-Series Datasheet for more details on built-in AIN.

Extended range

For extended channels, the positive channel can be any channel (even or odd) listed as a positive channel in the chart below. The negative channel number is the positive channel number plus 8 (listed under the “Negative Channel” the chart below).

Example 1: The positive channel is connected to AIN102 (AIN6 on the CB37 connected to X5). The corresponding negative channel is AIN110 (DAC0 on the CB37 connected to X5).

Example 2: The positive channel is connected to AIN64 (FIO0 on the CB37 connected to X3). The corresponding negative channel is AIN72 (AIN0 on the CB37 connected to X4).

Note that for some differential pairs, the positive and negative are located on different connectors.

Table 2. Channel numbers for analog inputs based on differential connection and CB37 connector

See 14.2 Extended Channels of the T-Series Datasheet for more details on extended ranges.

Specifications

Ground Offsets

A single-ended analog input measurement is the voltage difference between the analog input and ground at the A/D chip on the main device (e.g. U6 or T7).  If the voltage provided by a given signal is different than the voltage at the A/D chip, that results in error.

Suppose, for example, a thermocouple is connected to AIN0 and the adjacent GND terminal on a CB37, that is connected to X3 on a Mux80 via a 3 foot cable, and that is connected to a T7.  Suppose the remote end of thermocouple is at a temperature such that it is creating a voltage difference of 1600 µV between the AIN0 and GND terminals on the CB37.  Typically, the voltage at the CB37-AIN0 terminal will be the same voltage presented to the A/D chip, but the voltage at the CB37-GND terminal might be 280 µV higher than ground at the A/D chip due to other currents flowing on ground.  That means the A/D chip will see 1880 µV rather than 1600 µV, which is an error of roughly 7 degrees C.

Voltage drop on the AIN connection is not a concern as the only current on the AIN connection is the bias current.  The typical AIN bias current of the U6 or T7 is 20 nA, so even if the path from terminal to A/D chip had a high resistance of 10 ohms that would only be 200 nV of error.

Voltage drop on the ground connection can sometimes be a concern and is called ground offset error.  Just the normal power supply current of the Mux80 and CB37 can cause GND terminals on the CB37 to be 100s of microvolts higher than ground back at the A/D chip.  Any current sunk to GND by user connections will increase this difference.

One solution is to use the AGND terminal on the CB37.  AGND has its own dedicated path back to the main device, so as long as the user does not sink any current into AGND it will be at the same voltage as ground at the A/D chip.

To measure how much offset exists from a particular GND terminal to ground at the A/D chip, simply jumper the GND terminal in question to an unused AIN terminal and measure the single-ended voltage from that AIN channel.

Suggestions & Solutions:

A.  Use differential analog inputs.  Differential readings take the difference between 2 AIN lines and thus are not affected by ground offset.  For example with a thermocouple, connect thermocouple+ to a positive channel (AIN48 for example) and connect thermocouple- to a negative channel (AIN56 for example).  A resistor (100k would be typical e.g. CF14JT100K) from the negative channel to GND is also required, as the thermocouple cannot be totally floating (see the Differential Readings App Note).  Now configure and read AIN48 as differential.

B.  Use AGND for all passive sensors such as thermocouples.  Make sure not to connect anything to AGND that will sink/source any substantial current to AGND or offset will be created from AGND versus A/D chip ground.

C.  Use an extra AIN channel on the CB37 in question and jumper it to GND on the CB37 to measure the GND offset so it can be accounted for in software.

D.  Get rid of or at least reduce GND offset by minimizing connections (minimizing resistance) between the signal terminals and A/D chip, avoiding sourcing/sinking current to GND on the CB37, and adding a big fat wire from CB37-GND to U6-GND or T7-GND.

E.  Use a star ground, and have a single solid connection from that star ground to U6-GND or T7-GND.  For example, connect the negative leads of all signals to an external grounding post or grounding bar, and run a big fat wire from there to a GND on the main LabJack.

Software

The Mux80's extended channels (AIN48-AIN127) act just like normal channels (AIN0-AIN13) and are read the same way.  For example, one of the T7's built-in analog inputs can be sampled by reading "AIN0". To sample an analog input on the Mux80, you can read "AIN48". Similarly, AIN configurations like range and resolution are configured in the same way for extended channels as they are for normal channels.  Configurations that apply to ALL channels do include normal and extended.

Most of our customers write their own software, but there are various software options:

• T-series software options
• UD software options

Our LJLog and LJStream example programs allow you to read any 16 channels.  So they can read any channels on the Mux80, but not all of them at the same time.  There is a beta version of LJLogM that does allow lots of channels (up to 255), so that is a reason for some customers to consider the newer LJM devices (e.g. T7) rather than UD devices (U3, U6, UE9).

Another option for non programmers is DAQFactory, but the free Express version is limited to 8 channels.

Troubleshooting

MIO0-2 are used to control the MUX80 multiplexers; ensure the MIO are not being used as normal DIO while trying to take readings from the MUX80.

For initial testing, the same steps that are described in our Test an AIN application note can be performed. With T-series devices, the extended AIN registers (whose hardware mapping is described in Table 1, Table 2, and on the pinout page) can be read directly in Kipling using the register matrix tab. For UD devices, see the "U6 or UE9 only" guide below.

If there seem to be problems with incorrect readings, also check that V_MUX+ and V_MUX- are within specified limits by measuring the test points with respect to GND. The Mux80 does not use VM+/VM- from the main device at all, but rather has its own power supply circuit to convert 5V (VS) to ±13V (V_MUX+ and V_MUX-) for the mux chips. Note that with a CB37 connected to any of X2-X5, the screw terminals labeled VM+/VM- are actually connected to V_MUX+ and V_MUX-, so this is a another way to measure besides the test points on the PCB.

Troubleshooting - U6 or UE9 Only

It is possible to check Mux80 functionality in LJControlPanel by performing the following steps:

1. Open LJControlPanel
2. Select UD device and click Test
3. On test pane, locate MIO 00, MIO 01, MIO 02 checkboxes for both Digital Direction and Digital State
4. Check the boxes for all 3 MIO lines under Digital Direction
5. Check desired boxes under Digital State according to the following table.  Find the extended channel number to investigate, then trace across the row to the Digital State of MIO0, MIO1, and MIO2.  Set the output state to high (checked) for 1 and low (un-checked) for 0.
6. Trace the column up to AIN#, this is the analog input that your analog signal will appear on.