Automation Direct CLICK PLUS PLC Manual page 30

Chapter 4: PLC Communications
Exception Response (Exception Code)
When the slave CLICK PLUS PLC receives a request from the Modbus master that it cannot
respond to, the slave CLICK PLUS PLC sends an exception response to the Modbus master.
The CLICK PLUS PLC supports the following Exception Responses.
Code
01
Illegal Function
02
Illegal Data Address
03
Illegal Data Value
04
Slave Device Failure
4-30 CLICK PLUS PLC Hardware User Manual, 1st Edition, Rev. B – C2-USER-M
Exception Response (Exception Code)
Name
The CLICK PLUS PLC does not support the function code received from the
MODBUS master.
The MODBUS master tried to access to an invalid address.
The data length is zero or exceeds the maximum size.
The data for Write Single Coil is not FF00h (ON) or 0000h (OFF).
The PLC mode change request from the MODBUS master is not valid.
Password is locked.
When the PLC mode switch is in STOP position, the MODBUS master
requested to switch to RUN mode.
When the PLC mode switch is in RUN position, the MODBUS master requested
to switch to the Firmware Update mode.
Details of Exception Response