Omron SYSDRIVE 3G3RV Series User Manual page 296

• RS-422A (4-wire)
Communications Board
Code
SDA
SDB
RS-422A/485
RDA
interface
RDB
FG
9-pin D-sub connector
(Connector on cable: Male)
Note Turn ON the terminating resistance switch at all Inverters.
nMessage Format
In RS-422A/485 communications, the master sends commands to the slave, and the slave responds. The mes-
sage format is configured for both sending and receiving as shown below, and the length of data packets is
changed by the command (function) contents.
Message data
(Request message or response
The space between messages must support the following.
-80
6
B500-AL001 Link Adapter
Shielded cable
Pin No. Pin No.
1
2
6
8
Hood
RS-422A
Code
Pin No.
Fig 6.57 RS-422A Wiring
Slave address
(1 byte)
PLC to Inverter
Command message
Response message
24 bits long H5-06
setting
Fig 6.58 Message Spacing
Code
Code
9 SDA SDA
5 SDB SDB
RS-422A
6 RDA RDA
interface
1 RDB RDB
3 SG SG
7 FG FG
SDA SDB RDA RDB SG
9 5 6 1 3
RS-422A
Function code
(1 byte)
Inverter to PLC PLC to Inverter
Command message
24 bits long
5 ms min.
SYSDRIVE RV
Pin No.
Shielded cable Code
9 S
5 S
6 R
1 R
3
RS-422A
7
FG
7
SYSDRIVE RV
Shielded cable
Code
S
S
R
R
Error check
Communications
(2 bytes)
data
Time (Seconds)
Control cir-
cuit terminal
block (com-
munictions
terminals)
Control cir-
cuit terminal
block (com-
munictions
terminals)