PDA AI Acquire Waveform function

[Sprasad]

I am having trouble with this function on the PDA. It outputs a value even when nothing is plugged to the channel and it reads incorrect values when i test it with a signal. I used the same set up in the windows environment and used the windows VI and there are no errors. Any suggestions?
I am using a NI-6062E DAQ card
Thanks in advance

Prasad

[Bill B]

Hello Prasad,

Thank you for contacting National Instruments.

We have a patch for LabVIEW PDA that you can download and install that should help alleviate these issues. Please let us know if these problem persist after installing the patch. Here is a link to the patch:

http://digital.ni.com/softlib.nsf/websearch/7E48E83E0BCB025086256DB900533A0A?opendocument&node=132060_US

Regards,
Bill B
Applications Engineer
National Instruments

[Sprasad]

Thanks Bill.
I had the intsalled the patch. I reinstalled the patch again. There is an improvement. The signal now indicates whether a parameter was increased or decreased which was not the case before. The problem now is that theres a somewhat random offset to the signal. I tried 3 different sensors and I got random offsets in these siganls. This was not happening when i checked the signals with my laptop.

Thanks
Prasad

[Bill B]

Prasad,

You may need to scale your signal in software to remove any residual offset that may exist in your measurement.

Regards,
Bill

[Sprasad]

Thanks Bill
The offset is random so i am finding it difficult to scale the signal.

I had another question. Where could I get the pin out diagram for the CB-68LPBoard/SH-68-68EP cable?
Thanks
Prasad

[Bill B]

Prasad,

The 68-pin terminals of the cable and terminal block are the same as those found on your DAQCard-6062E. Please see page 4-2 of the 6062E User Manual. Here is a link to the manual:
http://digital.ni.com/manuals.nsf/websearch/637B5B318A8250AA86256BE3007B98A2?OpenDocument&node=132100_US

Regards,
Bill B.

[Sprasad]

Thanks for the pin outs.. I checked my connections. The PDA gives erroneous results when compared to the laptop. I use the DAQ card with the laptop and there seems to be no issue. Is it possible the 'Accquire waveform' function for the PDA is corrupted?

Thanks
Prasad

[Bill B]

Prasad,

Ensure that you have your signal connected to your DAQCard in DIFFERENTIAL mode. This is the only supported mode for PDA. You will need to connect the positive input to ACH0 and the negative input to ACH8 to measure on analog input channel 0 in DIFF mode.

Regards,
Bill B.

[Sprasad]

The signal is connected to the DAQ card in differential mode

Thanks
Prasad