Modbus Exception: Write to Read-Only Register/Coil

What does 23 hex mean?

This Modbus exception is returned when the master device attempts to write data to a register or coil that is configured as read-only by the inverter. The inverter rejects the command because it cannot modify the data at that address. This typically applies to monitor values or fixed system status indicators that are not user-editable.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Adjust the Modbus master's programming to only read from read-only registers/coils or direct write commands to appropriate writable addresses.