RS-232C Port Timeout Error

What does A528.05 mean?

This flag turns ON when a timeout error occurs during RS-232C communication. This indicates that a response from the connected device was not received within the expected timeframe after a transmission. This error is valid in Serial Gateway mode, NT Link mode, and for both Polling and Polled Units in Serial PLC Link Mode.

• The connected device is not responding or is offline
• Communication cable issues (disconnection, damage)
• Incorrect communication protocol or addressing settings
• Timeout parameter set too short for network latency or device response time

Click steps to track your progress.

1. 1

   Verify the connected device is powered ON and operating correctly

2. 2

   Inspect the RS-232C cable for continuity and proper connection at both ends

3. 3

   Check communication parameters, including device address and protocol settings, on both the PLC and the connected device

4. 4

   Adjust the communication timeout parameter in the PLC configuration if the connected device has a slower response time

5. 5

   Restart the RS-232C port by turning ON the Serial Port Restart Bit (A526.00) from OFF to ON