Scxi 1122 - strain gauge measurement problem

[Setu]

Hi all,
Has anyone ever used scxi 1122 and 1322 with labview? If so could you please post a vi so I could check my setup here?

I am measuring 8 quarter bridges with scxi 1122, 1322 and labview. I am using quarter bridge II configuration in MAX and a dummy resistor for half bridge completion. I need to get the mean of 100 samples for each channel.
If I configure AIConfig, AIStart and AIRead to scan rate of 100 per second, I get the wrong numbers to the test panel in MAX. If I scan each channel 100 times, then average them, it takes longer than a second.

Can anyone please suggest something? Perhaps I have wired them up incorrectly to the terminal block.

Thanks,
-Setu.

[Russell]

Setu,

Yes, compared to the other modules, you do have to sample slower with the 1122. There are other modules that will work faster though.

What do you mean by "wrong numbers to the test panel in MAX?" Do you mean if you scan the channels you get wrong values, but if you just sample one channel you get correct values? You have to use a long interchannel delay with the 1122 since it is relay multiplexed. This is why it probably works fine reading only one channel, but not with multiple. I'm guessing your connections are probably OK, if you can get good values.

I found a Knowledge Base and an example program that also might help.
SCXI-1122 Example
Knowledge Base 107C2818

--Russell