Wire Break vs Common Mode Error

Hi AutoGen_9483293,

Based on the provided sources, it appears that there is a diagnostic preferential order for the diagnostics you have enabled on your analog input module. When both wire break and common mode failure diagnostics are enabled, the common mode failure diagnostic can override the wire break diagnostic.

From the 'SIMATIC S7-1500, ET 200MP, ET 200SP, ET 200AL, ET 200pro, ET 200eco PN Analog value processing: # Diagnostics' source, it is noted that:

- Common mode error diagnostics can be triggered by various causes such as wiring errors, EMC disturbances, or sensor disconnections. This diagnostic can take precedence over other diagnostics like wire break.

- Wire break diagnostics are specifically for detecting interruptions in the electrical circuit, typically using the live zero technique for 4-20 mA signals.

When a wire break occurs, it initially triggers the wire break diagnostic. However, if the common mode error condition is also met, the system prioritizes the common mode error diagnostic, which then clears the wire break fault.

Even so, it occurs to me that when a type of wire fault error occurs, you should make an error logic to store that value in a separate variable and display it so that it does not step on the next ones that may occur.

I hope that it can serve you of help the commented thing.

Best regards!