Example

Example:

MODBUS interface of the client	COM1
Client writes to	Server 1
Data	wData := 7
Source address at server	wData : WORD
Target address at client	%MW0.8199 : 2007HEX = 8199DEC
The value of the WORD variable bBit on the client is written to %MW0.8199 on the server.

MODBUS request of the client

Server address	Function code	Server operand address		Data		CRC
		High	Low	High	Low	High	Low
01HEX	06HEX	20HEX	07HEX	00HEX	07HEX	72HEX	09HEX

MODBUS response of the server (mirrored)

Server address	Function code	Server operand address		Data		CRC
		High	Low	High	Low	High	Low
01HEX	06HEX	20HEX	07HEX	00HEX	07HEX	72HEX	09HEX

Parameterization \ of the COM_MOD_MAST Function Block inputs

EN	COM	SLAVE	FCT	TIMEOUT	ADDR	Number of words	DATA
FALSE -> TRUE	1	1	6	Application- specific	8215	1	ADR (wData)