sensor selection

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aqilahnadiah
qilanadia's picture
sensor selection

Hi labjack team, may i know whether this type of sensor (https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrt...) can connect directly to the 5V outlet from U12 DAQ ? 

Thank you.

LabJack Support
LabJack Support's picture
The sensor needs an

The sensor needs an excitation voltage of 3.0-5.5 volts at 0.8 mA, so yes you can power the sensor from +5V and GND on the U12.

The signal is 0.5 to 4.5 volts, so yes you can connect that to an analog input on the U12.

The sensor does not have DC response ... AC only.  You will want to make sure you sample fast enough to acquire the signal you are interested in:

https://labjack.com/support/datasheets/u12/datarates

Note that all our other devices are newer and much faster than the U12:

https://labjack.com/products/comparison

Here is our accelerometer app note.  I might add mention of this TE part as it looks very easy to use for dynamic accelerations.

https://labjack.com/support/app-notes/accelerometers

 

aqilahnadiah
qilanadia's picture
Thank you for the feedback

Thank you for the feedback labjack team.

What if I use this sensor with T7 pro? or I still need to find another sensor with DC response?

LabJack Support
LabJack Support's picture
It looks like your TE

It looks like your TE accelerometer will work great with a T7-Pro.  Use one of the analog output channels (DAC0) to generate a stable excitation voltage between 3.0V and 5.0V with Kipling (pin 3 of your sensor), connect pin 2 (GND) to the GND screw terminal on the T7, connect pin 1 (the output) to AIN0 of the T7, and then use LJStreamM to read AIN0 at a configurable speed between 1KS/s and 100KS/s.
Note: S/s: Samples per second

aqilahnadiah
qilanadia's picture
Thank you for the information

Thank you for the information labjack team, really appreciate it.

Can you give me a few suggestion plug and play vibration sensor tht compatible with the U12.? 

LabJack Support
LabJack Support's picture
Your TE sensor is compatible

Your TE sensor is compatible with the U12, but are you looking for other options?  You mentioned you are doing vibration measurements, and with vibration measurements you typically only care about AC response and DC response does not matter.

It appears that TE has acquired Measurement Specialties, so this is a good place to look:

https://www.te.com/usa-en/products/sensors/vibration-sensors/plug-play-a...

If you want a packaged sensor with a cable that has DC response, start here for options from TE:

https://www.te.com/usa-en/plp/plug-play-accelerometers/YG2dw.html?q=&d=5...

Sensors that can be powered from 5 volts (or less) are the most convenient, so ask them about that.

Doing a quick search, here are some other manufacturers you could check with for packaged MEMS accelerometers.  Avoid ICP & IEPE sensors as they are difficult to work with unless they have excitation and signal conditioning included:

http://www.pcb.com/products/productfinder.aspx?tx=14

https://www.silicondesigns.com/compare

http://www.jewellinstruments.com/sensors-and-controls-2/mems-acceleromet...

http://www.djbinstruments.com/products/piezoelectric-accelerometers/dc-mems

 

 

 

aqilahnadiah
qilanadia's picture
Thanks for the info labjack

Thanks for the info labjack team.

Currently, I'm using the TE sensor with T7 pro. Since the kipling based on LUA language, can you give me sample syntax to set the digital port to generate 3v to 5v excitation voltage.

Your help is much appreciated.

LabJack Support
LabJack Support's picture
You can just start by using a

You can just start by using a VS terminal to power your sensor:

https://labjack.com/support/datasheets/t-series/vs

Then if you decide you want something more stable, I would suggest a DAC terminal rather than a digital output.  You can use the Dashboard in Kipling to set either DAC line to 4.5 volts.

https://labjack.com/support/datasheets/t-series/dac

I don't see any reason to use Lua scripting here.

aqilahnadiah
qilanadia's picture
Thanks for your feedback,

Thanks for your feedback, right now im having problems to connect with the t7 pro with labview.

How i can ensure the t7 pro icon appear in labview function palette. I tried it but only the ljm icon appear. 

Before this i tried to put the u12 icons and it succeed (refer the attached image). But for t7pro, im stuck.

File Attachment: 
LabJack Support
LabJack Support's picture
A.  Start by reading about

A.  Start by reading about stream mode.  You will use stream mode to acquire waveform signals from your dynamic sensor:

https://labjack.com/support/datasheets/t-series/communication

https://labjack.com/support/datasheets/t-series/communication/stream-mode

https://labjack.com/support/software/api/ljm/function-reference/stream-f...

 

B.  Next, use LJStreamM.exe to acquire signals from your accelerometer and make sure the hardware is working as expected.  This will also let you experiment with stream settings (e.g. scan rate) to decide what stream settings you want to use.

 

C.  Next, go through the basics of LabVIEW.

LJM is the library for the T7-Pro.  Everything you see will say "LJM" not "T7".

To get going go through the "Getting Started" steps 1-6 here:

https://labjack.com/support/software/examples/ljm/labview

 

D.  Finally, open a stream example in LabVIEW to try streaming a waveform signal from your accelerometer.  I suggest "Stream Basic.vi".

 

aqilahnadiah
qilanadia's picture
Hi labjack team, how to know

Hi labjack team, how to know suitable excitation voltage to be used for this accelerometer since we can control the excitation voltage in the dashboard (kipling).

and

how to scale the output accelerometer voltage in labview?

thank you.

aqilahnadiah
qilanadia's picture
One more thing, how to

One more thing, how to correlate between voltage and acceleration? Since our output in V, but we interested to know the acceleration value as well.

LabJack Support
LabJack Support's picture
I suggest you set DAC0 to 4.5

I suggest you set DAC0 to 4.5 volts and use that for your excitation.  Use Kipling to set DAC0=4.5, and then go to the Power-Up Defaults tab to save that setting.

From your sensor's datasheet, the signal output has a bias voltage of Exc/2.  That means you need to know the actual value of the excitation voltage at all times so you can subtract Exc/2 from your readings.  I suggest you connect a jumper wire from DAC0 to AIN1 so you can use AIN1 to measure the actual value of your excitation voltage in real time.

If you have the 20g sensor, the output of the sensor is Exc/2 plus 100 mV/g.  That means if your excitation is 4.5 volts, the output of sensor will be:

-20g    0.25V
0g       2.25V
20g     4.25V

SensorOutputV = Exc/2 + 0.1*g
AIN0 = AIN1/2 + 0.1*g
g = (AIN0 - AIN1/2) / 0.1

Kipling does not do any scaling, but LJLogM and LJStreamM do.

 

aqilahnadiah
qilanadia's picture
Thnks for the feedback

Thnks for the feedback labjack team.

Hope you can reply several questions below:

 

1. Do this labjack has frequency hopping? 

2. Can we adjust the frequency hopping to meet industrial frequency?

2. If I have 2 labjack, can one labjack transfer its data to other labjack and both data from the 2 labjack send to a router?

3. If I want to buy the oem labjack type, can your company customize based on our preferences and can you the list down the customization option?

4. Can I customize the wifi module?

5. Is there any setting for sleep mode and idle mode for this labjack and how?

6. I try to read voltage using this TE accelerometer as mentioned above using labview. I set the excitation voltage to be 2.25V which is at 0g (acceleration). But when i read in labview, the value of g is negative value, may i know why this happen?

LabJack Support
LabJack Support's picture
1&2.  I am afraid I don't

1&2.  I am afraid I don't know what you mean by frequency hopping in this context.  You will have to explain further.

3.  No the T7s can't talk to each other.  Both need a connection to the host over USB, Ethernet or WiFi.

4.  At low volumes we can usually do the customization.  At higher volumes it should be done by an electronics shop that specializes in that.  Let us know what sort of customization you might want and we can let you know if it can be done:

https://labjack.com/support/datasheets/t-series/oem-versions

5.  What sort of customization would you want for the WiFi module?

6.  The T7-Pro does have the ability for a low power mode, but I don't think it has been implemented or supported.  I will check further.  Are you concerned about power usage?

7.  You can test your accelerometer like you describe right on the Kipling Dashboard.  You can use LabVIEW, but the Kipling Dashboard is a quick way to do your initial test of set DAC0=4.5 and read AIN0.  Connect DAC0 to Pin3:+EXC, GND to Pin2:GROUND, and AIN0 to Pin1:+OUT.  You should see that AIN0 reads 2.25 volts if there is no acceleration.  Use a voltmeter to check by measuring the voltage from DAC0 versus GND (4.5 volts) and AIN0 versus GND (2.25 volts).

 

aqilahnadiah
qilanadia's picture
Dear labjack,

Dear labjack,

 

Its okay, just ignore the question. What sholud I do if my data include noises, i already put window and filter function in the labview, but still the result is unsatisfied. Do you have any suggestions for tht? I think my labview programming is the main culprit if this problem. Or do i need to put amplifier or other components to get a good result?

 

thank you

LabJack Support
LabJack Support's picture
Noise can come from a lot of

Noise can come from a lot of different places. We will need to go through a few tests to find the source or the noise.

The first thing to do is make sure the labjack is working well. Remove all signals from the LabJack and connect a wire between an analog input and ground. If you want to test differential connect two adjacent AINs to GND. Verify that the noise level matches the specs here: https://labjack.com/support/datasheets/u12/appendix-a

If the U12 seems to be working properly then we will need to examine the signal source and connection.

The U12 is a 12-bit system, so when running at ±10V the resolution is ~ 5mV. It is tough to get below 2-4 bits of noise so 10-20 mV is the best we can expect.

aqilahnadiah
qilanadia's picture
thnks for the feedback

thnks for the feedback labjack team.

 

If I insist to use IEPE accelerometer with t7 pro. can you suggest what labjack accessories I need to buy for signal conditioning and external power supply.

 

regards.

LabJack Support
LabJack Support's picture
We do not offer any signal

We do not offer any signal conditioning for ICP or IEPE accelerometers:

https://labjack.com/support/app-notes/accelerometers

You will have to find a 3rd-party source for that so search for "iepe signal conditioner".  If you find any of interest post links here and we can look at them for you.  Here is one of the first results when I searched:

http://www.djbinstruments.com/products/instrumentation/signal-conditioning