1771 Module Response Not Valid

What does F018 mean?

This fault occurs when a 1771 I/O module responds to a request but its response data is deemed invalid or corrupted. This prevents the system from reliably using the module's status or input data.

• Faulty 1771 I/O module hardware.
• Electrical noise or interference on the 1771 backplane affecting data integrity.
• Incorrect configuration of the 1771 module.

Click steps to track your progress.

1. 1

   Inspect the 1771 I/O module's seating within the backplane and all associated field wiring for loose connections, corrosion, or damage.

2. 2

   Measure and verify the supply voltage to the 1771 I/O rack power supply and the specific 1771 I/O module, ensuring it is within the manufacturer's specified tolerance.

3. 3

   Verify the 1771 I/O module's configuration and addressing in the PLC program matches the installed physical module type and its expected input/output data format.

4. 4

   Check for external sources of electromagnetic interference (EMI) or radio-frequency interference (RFI) near the 1771 I/O rack and its communication cables that could corrupt data.