Omron SYSDRIVE RV Series User Manual page 313

RS-422A (4-wire)
•
Communications Board
Pin No.
Code
SDA 1
SDB 2
RS-422A/485
RDA 6
interface
RDB 8
FG
Hood
9-pin D-sub connector
(Connector on cable: Male)
Note Turn ON the terminating resistance switch at all Inverters.
Message 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.
PLC to Inverter
Command message
24 bits long
B500-AL001 Link Adapter
Code
Shielded cable Pin No.
9 SDA
5 SDB
6 RDA
1 RDB
3 SG
RS-422A
7 FG
Code SDA SDB RDA RDB SG
Pin No. 9 5
Fig 6.60 RS-422A Wiring
Slave address
(1 byte)
Inverter to PLC
Response message
H5-06 24 bits long
setting
Fig 6.61 Message Spacing
Code Pin No.
Shielded cable
SDA 9
SDB 5
RS-422A
RDA 6
interface
RDB 1
SG 3
RS-422A
FG 7
FG
6 1 3 7
Shielded cable
RS-422A
Function code Communications
(1 byte)
data
PLC to Inverter
Command message
5 ms min.
Communications Functions
SYSDRIVE RV
Code
Control cir-
S
cuit terminal
S block (com-
munications
R
terminals)
R
SYSDRIVE RV
Code
Control cir-
S
cuit terminal
S
block (com-
munictions
R
terminals)
R
Error check
(2 bytes)
Time (Seconds)
105
6-