Omron SYSMAC CS1W-SCB41-V1 Operation Manual page 144

RS-232C and RS-422A/485 Wiring
Serial
Communications
Board/Unit
Pin Signal
SD
RD
RTS
CTS
SG
Hood FG
FG
CS-series PLC
Serial Communications Board/Unit
SCU21
RUN
RUN RDY
ERR/ALM
ERC ERH
INH
SD1 SD2
RD1 RD2
PRPHL/COMN
SYSMAC CS1G
PROGRAMABLE CONTROLLER
0 CPU42
OPEN
MCPWR BUSY
OPEN
PORT1
PERIPHERAL
PORT2
PORT (RS-232C)
Hood and GR are
internally connected.
Grounding the GR terminal
grounds the Hood (FG).
2. Combine signal wires and SG (signal ground) wires in a twisted-pair cable.
At the same time, bundle the SG wires to the connectors on the Serial
Communications Board/Unit and the remote device.
3. Connect the shield of the communications cable to the Hood (FG) terminal
of the RS-232C connector on the Serial Communications Board/Unit. At
the same time, ground the ground (GR) terminal of the Power Supply Unit
on the CPU Rack or CS Expansion Rack to 100 Ω or less.
4. A connection example is shown below.
Example: Twisted-pair Cable Connecting SD-SG, RD-SG, RTS-SG, and
CTS-SG Terminals
Remote device
Signal
RD
SD
CTS
RTS
SG
FG
Shield
Note The Hood (FG) is internally connected to the ground terminal (GR) on the
Power Supply Unit via the CPU Rack or Expansion Rack. Therefore, FG is
grounded by grounding the ground terminal (GR) on the Power Supply Unit.
Although there is conductivity between the Hood (FG) and pin 1 (FG), connect
the Hood (FG) to the shield because the Hood (FG) has smaller contact resis-
tance with the shield than pin 1 (FG), and thus provides better noise resis-
tance.
Power Supply Unit
PA204S
POWER
L2/N
AC100V-120V/
AC2100-240V/
INPUT
L1
100-200
CLOSE
200-240
OPEN GR
DC24V/0.8A
OUTPUT
Ground to 100 Ω or less
Actual Wiring Example
SG signal wires
XM2S-0911-E
CJ-series PLC
Power Supply Unit
PA205R
SYSMAC
POWER CJ1G-CPU44
PROGRAMMABLE
CONTROLLER
L1
AC100-240V
INPUT
L2/N
GR
RUN
OUTPUT
AC240V
DC24V
Ground to
100 Ω or less.
Section 3-4
Twist the shaded lines to make
them thinner and connect to Pin
No. 1 (FG). Cover this section
with heat-shrink tube to avoid
contact with other sections.
Bundle the SG wires.
Aluminum foil
Serial
Communications
Unit
SCU41
RUN ERC RD1 TER1
SD1
RUN
ERR/ALM
INH
RDY ERH SD2 RD2
PRPHL
COMM
TERM
UNIT
OFF ON
NO.
WIRE
OPEN 2 4
PORT1
MCPWR (RS422
/485)
BUSY
PERIFHERAL
PORT2
PORT
Hood and GR are
internally
connected.
Grounding the GR
terminal grounds
the Hood (FG).
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