Omron CJ1W-SCU22, Руководство по эксплуатации, Страница: 227 / 478

5-35
5 Serial Gateway
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
5-6 Co
mm
u
n
ication
s Fram
es
5
5-6-2 Modb
us-R
T
U
z
Response Frame
Frame before Conversion
Header
Modbus-RTU frame
Start (silent
interval of
3.5
characters)
(See note.) End (silent
interval of
3.5
characters)
(See note.) Slave
address
(1 byte)
Command
FUNCTION
code
(1 byte) Communications data
(n bytes) Error
check
CRC
(1 byte)
Command
end code
Frame after Conversion
Modbus-RTU
(command section only)
FUNCTION
code (1 byte) Slave
address
(1 byte)
SRES MRES SRC Remote
network
address
(DNA) Remote
node
address
(DA1) Remote
unit
address
(DA2) MRC
04 Serial port
allocated
address 00 hex Serial
port
unit
address 28
or local
network
address or local
network
node
address
Etc.
User-
speci-
fied User-
speci-
fied Communica-
tions data
(n bytes)