I am using a SNAP-OAC-EB2 with 12 analog input modules in a 16 slot rack. Each of the input modules has 8 analog inputs. I am measuring temperature with this system.
Every once in a while (about 1-2 times per week), all of the inputs into one module will produce a "-QNAN" for about 2 to 3 minutes, then resume working correctly. This has occurred on several different modules. Whenever it happens, it affects all 8 inputs into the module.
Anyone have any clues as to what might be causing this?
The SNAP system is connected to a Controllogix PLC with an ethernet connection through a Stratix 8000 switch with an expansion module (18 ports in total). The PLC and the switch are working normally.