User manual

5 Universal (General-purpose communication)
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5.4.3.2 Response slave part
Station Function code Data area
CRC
L H
① ② ③ ④
Item Description
①Station
It is slave station (HEX) for confirmation about Query.
②Function code (HEX)
Transmits same function code sent by Master for confirmation about
Query.
③Data area (HEX)
Transmits data related with function code. The length is variable.
④CRC(HEX)
It is error check area. It calculates using CRC-16 code.
It consists of 2btye. (Lower 1byte of CRC) + (Upper 1byte of CRC).
(1) Read Coils(Func01-01H)
Slave
Address
(station)
Function
(command)
Byte Count
(the number
of data byte)
Data
(data)
Data
(data)
Data
(data)
Data
(data)
1Byte 1Byte 1Byte 1Byte 1Byte 1Byte 1Byte
Error Check
(CRC16)
Lo(lower) Hi(upper)
1Byte 1Byte
(2) Force Multiple Coils(Func15-0FH)
Slave
Address
(station)
Function
(command)
Starting Address
(starting address)
No. of Coil
(the number of coil)
Error Check
(CRC16)
Hi(upper) Lo(lower) Hi(upper) Lo(lower) Lo(lower) Hi(upper)
1Byte 1Byte 1Byte 1Byte
1Byte 1Byte 1Byte 1Byte
(3) Read Holding Registers(Func03-03H)
Slave
Address
(station)
Function
(command)
Byte
Count
(the
number
of data
byte)
Data Data Data
Hi
(upper)
Lo
(lower)
Hi
(upper)
Lo
(lower)
Hi
(upper)
Lo
(lower)
1Byte 1Byte 1Byte 1Byte 1Byte 1Byte 1Byte
1Byte 1Byte
Error Check
(CRC16)
Lo(lower) Hi(upper)
1Byte 1Byte