1520 Strain Measurement

[Sandeep]

Hello All,
I am using SCXI 1520, Terminal Block 1314 and DAQ 6035 E Card, for
Strain Gauge Measurement.
We have got a Strain Gauge of 120 Ohm with the NI Hardware which was
connected to CH02(One of the 8 channels provided), Now my problem is
that if I connect the Strain Gauge to some other channel(except Channel
2) I am not able to get any readings , and if I reconnect it back to
Channel 2 it gives prorper results.
I have connected the strain Gauge in
a Quarter bridge Configuration(obviously for a Single Strain Gauge) as
per the circuit diagram provided correctly.
I have Pentium -4 , 256MB RAM, Win XP SP2 machine.
Could anybody please try to explain where I am going wrong.
With Regards
Sandeep

[devchander]

Did you check it on MAX  or by using a LabVIEW program??

Assuming that all you have got your wiring correct, the channel addressing in your program correct,  it looks like a have a hardware malfunction

Contact your local NI Application Engineer

[Steven_T]

I agree, please check this measurement in MAX by setting up a DAQmx Strain Gauge Task, or by using the test panels associated with the chassis if you are using Traditional DAQ.  What happens when you change the channel you are using and test it using MAX?  Is the signal responsive, but inaccurate?  Is it just displaying 0, 10, -10? 

If you are able to measure correctly, then just make sure you are changing the channel in your program.

If the signal is there and responsive with what is happening to the strain gauge, but inaccurate, you may have an offset error that can be corrected with the calibration resistor.  The completion resistors of the 1520 should be checked as well.  Make sure they are the correct values. 

https://www.ni.com/docs/en-US/bundle/370288a/resource/370288a.pdf

The DAQ Driver version would also be helpful if you are still having problems.