The problem is still occurring and I still don't get any error codes to trigger anything off of while the code is running. The only errors I can see occur when i stop the program and try to restart it, resulting in a code stating the DAQ is already in use. I did manage to get lucky a record a video of the problem. It looks like the DAQ stop reading data consistently, resulting in a 'flickering' of the inputs. After a bit of time the flickering stops, but the outputs stop reacting to the software. According to the software the outputs are being written successfully, but the physical digital out voltages never change. The only way to rectify this is to re-set the DAQ from NI max. The video is linked below on a google drive. The error starts occurring at about 1:45. I do what I can to show relevant parts of the program when the glitch occurs.
Has this issue always existed or did it just start to happen?
Do you have back-EMF surge protection diodes across your relay coils?
What is the P/N of the relays being driven by the 9375? Wonder if you are exceeding the maximum current specifications of the module.
I only recently noticed the flickering, so I think it is a new issue. If this was happening all along, then it is at least more frequent now.
No, I do not have a diode across the relay coil.
The relays in use are Omron LY1F 12VDC relays.
Personally, I would start by replacing the 9375 module with a known good one.
If that works then I would suggest putting reverse biased diodes across each relay coil (i.e. 1N4004).
Yea, my thoughts exactly. I have another card on the way and will be trying it as soon as it arrives. In the meantime I'll see if we have any diodes around.