I have a 20 kg load cell, 350 Ohm, 2mV/V that I have used before. With a 10 V excitation it has an offset of about 2mV and generates close to 20 mV full scale as expected. I connected it to an NI 9237 module using the RJ-50 connector (full-bridge). I've verified the wiring twice, checked the connectivity and resistances at the connector and found everything in order. When I try to read the load cell using either MAX or the DAQ Assistant in LabVIEW, I get a constant excitation voltage of 10.49V regardless of the EX setting (2.5, 5, or 10), and I get a constant 25mV/V output. Calibration also fails. What is my next troubleshooting step?
If the calibration fails in MAX and you're getting a railed 10.45 Volts Excitation, I'd say the 9237 is in need of repair/replacement. You can run a self-test in MAX and if that fails, it's busted for sure. You can contact the RMA department at NI and they will be able to give you a quote. Call (866) 275-6964.