RS-232C Port Overrun Error

What does A528.04 mean?

This flag turns ON when an overrun error occurs during RS-232C communication. This means the CPU was unable to process received data before the next character arrived, leading to data loss in the receive buffer. This error flag is valid in Serial Gateway mode and for Polled Units in Serial PLC Link Mode.

• The CPU is too busy to process incoming data at the current baud rate
• The connected device is sending data too quickly
• Insufficient buffer space on the receiving side

Click steps to track your progress.

1. 1

   Reduce the baud rate setting for the RS-232C port to allow the CPU more time to process data

2. 2

   Check the connected device's transmission settings to see if its data transmission rate can be lowered

3. 3

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