SignalExpress
Signal Express logs the same value continuously when attempting to capture voltage from strain gauge
I am using a cDAQ9188 (ethernet connection) with NI9237 (strain gauge) and NI9211 (thermocouple) cards to log the voltage from a quarter bridge strain gauge and the temperature adjacent to the bridge in order to temperature compensate the signal myself in post-processing. When I view the signal in NI MAX, both temperature and voltage appear and respond as expected, however when I attempt to log data in Signal Express 2015 (V15.0.0) the voltage just appears as the same value logged continuously. This value happens to be the minimum value of the signal input range but even changing that parameter keeps the logged value as -25mV.
The thermocouple data logs fine however whatever I try, I can't get anything meaningful to log from the strain gauge. I've configured as both "custom voltage with excitation" and "bridge V/V" with no change. I also noticed that if I set “Full Bridge” in NI MAX it gives me the same value as the one signal express is logging, so it implies to me that signal express is seeing my gauge as a full bridge even though I've configured it as a quarter bridge. It's a shame I can't just log the data from the Test Panel in NI MAX (can I?!).
I've attached some screenshots, any help that anyone can offer would be really appreciated as this is winding me up!
Dave
