Omron CS1W-SCU21 Operation Manual page 321

E5#J Temperature Controller Protocol
‡ RS-485 2-wire Connections
Serial Commu-
nications Board/Unit
RS-485: D-sub
9-pin female
Signal
name
SDA
SDB
*1: Set the 2-/4-wire switch
to the 2-wire setting.
*2: Turn ON the terminat-
ing resistance switch.
Note 1. The connection configuration is a one-to-one or a one-to-N configuration. Using a one-to-N configu-
ration, up to 32 units can be connected including the Serial Communications Boards Unit.
2. The maximum cable length is 500 m. Use shielded twisted-pair cable.
3. Connect terminating resistance to the devices only at both ends of the transmission path.
4. The total terminating resistance at both ends must be at least 100 Ω for RS-422A or 54 Ω for RS-485.
Select Remote Mode (Sequence No. 200 (Hex 00C8))
Switches the Controller to remote mode.
Send Data Word Allocation (3rd Operand of PMCR(260))
First word of send
data
Receive Data Word Allocation (4th Operand of PMCR(260))
None.
302
Signal name
Terminal A
Terminal B
Signal ground
E5AJ
RS-485:
Pin Terminal Block
No.
Ter- Signal
minal
name
Shell
Shield
Shield
+0
Number of send data words
+1 (Undefined)
Offset Contents (data format)
+0 Number of send data words
(4 digits Hex)
+1 Unit No. (2 digits BCD)
Abbreviation
A
B
SG
Terminating
resistance
Terminator switch
E5AJ
RS-485:
Terminal Block
Signal
Ter-
name
minal
Unit No.
Appendix G
Signal direction
I/O
I/O
---
SN751177N
or equivalent
Terminating resist-
ance (240 Ω) is
connected via the
terminator switch.
Data
0002 (fixed)
00 to 31
Pin No.
26, 28
25, 29
27