Schneider Electric LUFP9 user manual Code Name Description of the exception Exception

11. Appendix E: Modbus Commands

Code	Name of the	Description of the exception
	exception
16#01	ILLEGAL FUNCTION	The query’s “Function” command code is not implemented in the Modbus slave
		software, or it is unable to process it for the moment.
16#02	ILLEGAL DATA	The combination of the query’s “Starting Address” and “No. of Registers” fields
	ADDRESS	(or assimilated fields) gives access to one or more addresses which are not
		accessible on the Modbus slave.
16#03	ILLEGAL DATA	The value of one of the Modbus query’s fields is outside the authorized limits.
	VALUE	This error does not affect the content of the “Data” (or assimilated) fields, as this
		error only takes account of the fields used for managing the Modbus protocol.
16#04	SLAVE DEVICE	An unrecoverable failure has occurred when processing the command.
	FAILURE
16#05	ACKNOWLEDGE	The Modbus slave informs the gateway that it has accepted the command
(1)		(acknowledgement), but that it will take too long to process it and it cannot afford
		to wait for the completion of this process before sending a response.
		The gateway should transmit subsequent queries in order to determine whether
		the command has finished or not.
16#06	SLAVE DEVICE	The Modbus slave informs the gateway that it is already in the process of
(1)	BUSY	running a command and therefore it cannot run the one transmitted to it.
		So the gateway should re-transmit the query subsequently.
16#07	NEGATIVE	The Modbus slave informs the gateway that it cannot process the requested
(1)	ACKNOWLEDGE	command. This exception only affects commands 13 and 14 (16#0D and
		16#0E). These functions are not part of the standard Modbus commands and are
		not described in this document.
16#08	MEMORY PARITY	The Modbus slave informs the gateway that it has detected a parity error on the
(1)	ERROR	access to its own memory. This exception only affects standard commands 20
		and 21 (16#14 and 16#15) which are not supported by the gateway.

(1) Please see the standard Modbus documentation for further information about these various cases.

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