SCXI-1581 reading bad temperatures

[miller.michael052410]

Hello,

I am a summer intern and I'm trying to find some help with the SCXI-1581 module. We had a major failure while testing a motor and it damaged some of the test equipment. We replaced everything that appeared to be damaged and tried to reboot the test system. Everything worked fine except for this module. I am using a 100 ohm RTD to test the various channels and I am getting a consistent wrong temperature. Instead of the 26 to 27 celcius ambient temperature, I am getting -243 to -244 celcius. It seems as if there might be a scaling factor that is causing the temperatures to record these low values.

As part of my troubleshooting process I took the SCXI-1581 module out the damaged test machine and replaced it with the same module from another machine. The temperature readings read properly for all the channels I tested. I then took the good module and put it back in the working machine and it still read appropriate temperatures. With that little check done I took the bad module and placed it in the working machine and ended up reading bad temperatures. At this point I had concluded that the module must be bad and replaced the good module back in the working machine. As a final check I tested the temperatures again and now the good module is reading the same bad temperatures as the other module.

I find it hard to believe that mearly placing the bad module in the working machine was enough to damage the good module as well. So my question is, is there some way to adjust the scaling factor or does the SCXI-1581 module need to be replaced? Is there something else I can do to make these modules work?

I may not have provided enough information and for that I appologize. I am not 100% familiar with this equipment but I will do my best to provide any additional information that might be required.

Thanks

[JasoNI]

Hello,

Could you clarify what is working and what is not? If we call the test system that had the major failure “System A” and the other test system that was working fine “System B” as well as having the corresponding SCXI-1581 modules as “Module A” and “Module B” respectively, let me know if the following is true:

-System A failed and, after replacing the necessary parts, Module A was still not working

-Module B was put in System A and the system functioned properly

-Module A was placed back in System A and still did not function

-Module B was placed back in System B and no longer functioned

In regards to scales, we can create custom scales in Measurement & Automation Explorer. I have included a link below that details what these scales are and how we can use them. I am not sure if this will resolve your issue, but it may be helpful after we fully understand it.

Custom Scales: http://digital.ni.com/public.nsf/allkb/0464919A11C092E386256D800079C3BB

Regards,

Jason D

Applications Engineer

National Instruments

[miller.michael052410 · Accepted solution]

Thanks for the reply.

My boss and I looked into it some more and found both cards to be working just fine. The error was in the RTD we were using to test the card.

[maruthisrinivas]

Hello Miller,

We are facing the same issue as posted by you. You can see our configuration from the following attachment. All of a sudden one of our RTD connected to channle 0 was showing --243 to -244 celsius (All the remaining RTD's were working properly). As part of trouble shooting, I changed the RTD connection to an empty channel and it was reading a value -63 to -64 celsius. As suggested by an Applications Engineer from NI, we replaced our SCXI-1102B module with a new one, still the error remains the same.

I apologize if I miss some information. Please let me know how you resolved this issue working with your boss.

Thanks in Advance,

Maruthi.