I found the same problem when IEPE enable. The current channel is connected with a 50 ohm short circuit.
Two MCC172 boards are installed in the current equipment. When electrical noise occurs, the other three channels also appear at the same time.
I tried to use the Raspberry Pi 3B and 4B, and replaced different power adapters and different MCC 172 boards. The problem still exists.
However, the data is normal in the IEPE disable.
heyihao got a reaction from skycraper3 in Periodical spikes when using MCC 172 and so on