Modbus-Ascii - Omron SYSMAC CS1W-SCB41-V1 Operation Manual

Communications Frames
Response Frame
6-8-3

Modbus-ASCII

Command Frame
Frame before Conversion
FINS header
Remote Remote
network node
address address
(DNA) (DA1)
Serial port 00 hex
allocated
address
or local or local
network network
address node
address
Frame after Conversion
Header Slave address
":" (ASCII code
(ASCII code 2 characters:
3A hex) 2 bytes)
Frame before Conversion
Start (silent Slave
interval of
address
3.5
(1 byte)
characters)
(See note.)
Frame after Conversion
FINS header
Remote Remote Remote
network node unit
address address address
(DNA) (DA1) (DA2)
Serial port 00 hex Serial
allocated port
address unit
address
or local or local
network network
address node
address
FINS command
Remote Etc. MRC SRC
unit
address
(DA2)
Serial 28 05
port
unit
address
Modbus-ASCII frame
FUNCTION code Communications data
(ASCII code (ASCII code n characters)
2 characters:
2 bytes)
Modbus-RTU frame
FUNCTION Communications data
code (n bytes)
(1 byte)
FINS command FINS end code
Etc. MRC SRC MRES SRES
28 04 User- User-
speci- speci-
fied fied
Modbus-ASCII
(command section only)
Slave FUNCTION Communications data
address code (ASCII code n characters)
(ASCII code (ASCII code
2 characters: 2 characters:
2 bytes) 2 bytes)
LRC CR
(2 ASCII (0D hex)
characters:
2 bytes)
Section 6-8
Error End (silent
interval of
check
3.5
CRC
characters)
(1 byte)
(See note.)
Modbus-RTU
(command section only)
Slave FUNCTION Communica-
address code (1 byte) tions data
(1 byte) (n bytes)
LF
(0A hex)
239