My boss and I are digging into some legacy software that interfaces with our CompactDAQ systems, and ran into a few questions regarding module excitation since we are unfamiliar with how it was set up in the first place. As a starting point, we have NI-9218 and NI-9237 modules interfacing with a cDAQ-9178. Here is the list of questions posed to me that I would like to better understand:
"The 9218 can provide 12V, 3.3V, or 2V of excitation, depending on measurement type.
The 9237 can provide 2.5 V, 3.3 V, 5 V, or 10 V of excitation.
Both modules include an external excitation connector, but I’m not sure what power source to connect.
Can any dc voltage source be used? Or does the source need to be the same voltage as the excitation setting?
In other words, can an external 12V power source always be connected? Or do I need to use a 3.3V source if my transducers are using 3.3V excitation?"
Please also see the images for more context. Also, we had a question about what would happen if we supplied an Excitation Value outside the specified values to the DAQmx Channel Property Node (e.g., for a 9218 channel, what if we specified a value of 5 to the AI.Excit.Val instead of 12, 3.3, or 2)?
Thank you!
