« Close

Datasheets and User Guides

App Notes

Software & Driver


2.11 - DB15

The DB15 connector brings out 12 additional I/O. It has the potential to be used as an expansion bus, where the 8 EIO are data lines and the 4 CIO are control lines. The EIO are flexible I/O as described in Section 2.5, so can be used as digital input, digital, output, analog input, timer, or counter.

In the Windows LabJackUD driver, the EIO are addressed as digital I/O bits 8 through 15, and the CIO are addressed as bits 16-19.

0-7    FIO0-FIO7
8-15   EIO0-EIO7
16-19  CIO0-CIO3

These 12 channels include an internal series resistor that provides overvoltage/short-circuit protection. These series resistors also limit the ability of these lines to sink or source current. Refer to the specifications in Appendix A.

All digital I/O on the U3 have 3 possible states: input, output-high, or output-low. Each bit of I/O can be configured individually. When configured as an input, a bit has a ~100 kΩ pull-up resistor to 3.3 volts. When configured as output-high, a bit is connected to the internal 3.3 volt supply (through a series resistor). When configured as output-low, a bit is connected to GND (through a series resistor).

Table 2.11-1. DB15 Connector Pinouts

DB15 Pinouts        
1 Vs   9 CIO0
2 CIO1   10 CIO2
3 CIO3   11 GND
4 EIO0   12 EIO1
5 EIO2   13 EIO3
6 EIO4   14 EIO5
7 EIO6   15 EIO7
8 GND      


Figure 2.11-2. Standard DB15 pin numbers looking into the female connector on the U3



Please explain how the EIO and CIO map to the 12 pins on the DB15 connector. Are there ground pins too?

The DB15 connector has 15 sockets.  The mapping is specified in Table 2.11-1 above.

The pin/socket numbers are actually printed on the face of the female DB15 connector, but can be hard to see.  Looking at the connector, pin 1 is at the upper-right and the top row goes right-to-left 1 through 8.  Pin 9 is at the bottom-right and the bottom row goes right-to-left 9 through 15.

Is it possible to move Asynchronous communication interface (UART) over to DB15?

So far I've been able to use configIO(TimerCounterPinOffset =8), but when I try to enter value higher than 8, it returns an error ("INVALID_OFFSET (100)).

I am using LabJack U3-LV with windows 8 PC and interfacing to it via Python (u3.py and LabJackPython.py for Close())

Yes.  TimerCounterPinOffset=8 is the max value, but 8 does move it to the DB15 connector since 8 is EIO0.  If you want to move Asynch TX and RX even higher, you can enable both timers and both counters to push the asynch lines up to EIO4 & EIO5.  See Sections 2.9 & 4.3.12.