Example¶

Example:¶
MODBUS interface of the client	COM1
Client writes to	Server 1
Data	awWriteWord[0] := 1 awWriteWord[1] := 2 awWriteWord[2] := 3
Source address at server	awWriteWord : ARRAY[0..2] OF WORD
Target address at client	%MW0.8193 : 2001HEX = 8193DEC
The values of the WORD variables awWriteWord[0]..awWriteWord[2] on the client are written to %MW0.8193..%MW0.8195 on the server.

MODBUS request of the client¶
Server address	Function code	Server operand address	Number of words	Number of bytes	Data	Data	Data	CRC
Server address	Function code	High / Low	High / Low	Number of bytes	High / Low	High / Low	High / Low	High / Low
01HEX	10HEX	20HEX / 01HEX	00HEX / 03HEX	06HEX	00HEX / 01HEX	00HEX / 02HEX	00HEX / 03HEX	C0HEX / 84HEX

MODBUS response of the server¶
Server address	Function code	Server operand address		Number of words		CRC
Server address	Function code	High	Low	High	Low	High	Low
01HEX	10HEX	20HEX	01HEX	00HEX	03HEX	DAHEX	08HEX

Parameterization \ of the COM_MOD_MAST Function Block inputs¶
EN	COM	SLAVE	FCT	TIMEOUT	ADDR	Number of words	DATA
FALSE -> TRUE	1	1	16	Application- specific	8193	3	ADR (awWriteWord[0])