Losing 1 channel on Scxi -1000 - 1125/1327

[jkleinjans]

Hello,

I am have an issue with one losing 1 channel on my scxi-1000 chassis.  I am running a motor life test on 8 motors using labview for daq as well as cycle control.  Two temps and 1 current are being measured on each motor.  In the scxi 1000 chassis I have 3 scxi 1125's with scxi -1327 connection blocks.  On two of the 1125/1327's I am measuring Temperature with J-type thermocouples, these 16 channels are all behaving.  The 3rd 1125/1327 I am using to measure motor current with DC current shunts 50A/50mV.  All of these channels are also working except for one.  When I start the labview program the channel is working fine, but after some amount of time (<1hr to >12hrs) the channel drops to 0v.  If I reset the chassis from MAX the channel will work again for a while then repeat the failure mode.

Any help or suggestions will be most appreciated.

Thanks,

Joe 

[Elijah_K]

Use a multimeter to verify that the module is reading the voltage incorrectly.  Try using a different channel to read the input to the problematic problem and see if it exhibits thte same behavior.  Also, instead of using your LabVIEW program use the test panels in measurement and automation explorer.  This will help eliminate software as the cause of the problem.

The goal at this point is to narrow down the source of the problem.  Let me know the results of my recommended tests and we can troubleshoot it from there.

In the unlikely case that it proves necessary to return your module for repair, you'll need to call us here at National Instruments.  For informaiton on this, visit ni.com/support

[jklein]

Thanks for your response.   I swapped 1327's with no luck, but when I switched the 1125 with one from another slot it seemed to help.  Both are working in their new slots.  I will keep an eye on it to see if it continues to function properly.

Any guess why it works in one slot and not the other?

Thanks agian for your time.

Joe K.

[Logan_K]

Out of curiosity - have you looked closely at the other channels to see if anything peculiar is happening?

What input range are you using on Channel 0 and what attenuation setting to do you use for the SCXI-1327?

Finally, what is the part number for your SCXI-1125? If you look on the back of your module you should see a sticker with a serial number and part number. The part number should be something like "185959F-01" but the letter might be different.

Thanks,
Logan