weirdly fluctuating inaccurate voltages reported using FP 1000

[kate aubrecht]

I have been using FP-100 with an FP-AI-100 and LabView for a couple years to monitor two voltages- one is a trigger and the other is the output from a detector. It has been working fine until today. For both voltages, it is reporting numbers that jump about within the reporting range (-6 to 6 volts). I used a voltmeter to measure the voltages at the output from the instrument I am monitoring- they are the fine- the problem is the Field Point unit. I see the same fluctuating values using both Field Point Explorer and LabView. I switched the wires to two different channels- it didn't help. What should I try?

[JohnM 64]

Hi Kate,

It sounds like you are following the proper troubleshooting procedures. You have verified that the signals coming into the unit are still giving good values, and you have tried different input channels on the FP-AI-100. If you are seeing the wrong values in FieldPoint Explorer, then you will not be able to get the good values in LabVIEW, so the problem is somewhere imbetween.

There are a couple of things you could try... first, you could try using a different serial cable for connecting the FP-1000 to the computer in case that is the faulty part. You could also try a different AI module if you happen to have access to one. That could tell us if the problem is with the AI module or with the FP-1000 controller module.

If none of this solves th
e problem, it is possible that the hardware has sustained some type of error. If you feel this is the case, I recommend contacting NI through technical support, either email or phone, in order to finalize troubleshooting and perhaps have it sent in for repair if necessary.

-JohnM

[Aaron_G]

Kate,

In addition to the troubleshooting advice provided by John, I would recommend that you check the power supply that is feeding the FP-1000 and the sensors. If the supply is noisy, it may be effecting the readings.

Regards,
Aaron