We have (39V) vibration transducers that send 150mV/in/sec@80hz. We've been having problems lately so I contacted the manufacturer of these 4-131-0103 sensors and found out that they recommend annual calibration testing of the sensors, which they can do. The problems I'm seeing are biased and fluctuating signals. I'm concerned about problems with the wiring and controller. I'm curious if it's possible to use a function generator to test the cabling / controls. For example connect a 0.75V RMS, 84Hz test signal at the local JB and/or AIO card, and see 6in/sec on the display. I did read the procedure that has you using the NATD and the HSAA card, but I'm hoping there's another way, Though I think we actually do have the NATD/cables hiding around here somewhere.