Modbus Slave Illegal Data Address

What does I x .Slave.IllegalDataAddress mean?

This boolean tag indicates that the Modbus master requested access to a Modbus register address that is outside the valid range defined for the slave module. A value of 1 (Occurrence) means the slave received a request for a memory location it does not support. This prevents the slave from fulfilling the master's request.

• Modbus master application attempting to read or write to an non-existent or out-of-range register address
• Incorrect Modbus map configuration in the master application
• Firmware issue with the slave's internal address mapping or register definition

Click steps to track your progress.

1. 1

   Review the Modbus master's application code to ensure all Modbus register addresses requested are within the valid range for the slave module.

2. 2

   Consult the slave module's documentation for the correct Modbus register address map and verify configuration.

3. 3

   Verify the Modbus master's configuration for correct address offsets and data lengths in its requests.