
3-19
3 Installation and Wiring
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
3-3 RS-23
2C and
RS-42
2A/485 Wiring
3
3-3-1 R
ecomme
nded RS-2
32C Wir
ing
Examples
3-3
RS-232C and RS-422A/485 Wiring
It is recommended that RS-232C cables be connected as described below especially when the Serial
Communications Unit is used in an environment where it is likely to be subject to electrical noise.
1
Always use shielded twisted-pair cables as communications cables.
2
Combine signal wires and SG (signal ground) wires in a twisted-pair cable. At the same time,
bundle the SG wires to each of the connectors on the Serial Communications Unit and the
remote device.
3
Connect the shield of the communications cable to the Shell (FG) terminal of the RS-232C con-
nector on the Serial Communications Unit. At the same time, ground the ground (GR) terminal
of the Power Supply Unit on the CPU Rack or Expansion Rack to 100
Ω
or less.
The Shell (FG) is internally connected to the ground terminal (GR) on the Power Supply Unit via
the CPU Rack or Expansion Rack. Therefore, ground the ground terminal (GR) on the Power
Supply Unit to ground the FG. There is conductivity between the Shell (FG) and Pin 1 (FG). To
minimize contact resistance between the Shield and the FGs and improve noise resisance, con-
nect the two FGs, i.e., Shell and Pin 1, to Shield.
A connection example is shown below.
Example:Twisted-pair Cable Connecting SD-SG, RD-SG, RTS-SG, and CTS-SG Terminals
3-3-1
Recommended RS-232C Wiring Examples
Recommended cable model
Manufacturer
UL2464 AWG28x5P IFS-RVV-SB (UL-approved)
AWG28x5P IFVV-SB (Not UL-approved)
Fujikura Ltd.
UL2464-SB (MA) 5Px28AWG (7/0.127) (UL-approved)
CO-MA-VV-SB 5Px28AWG (7/0.127) (Not UL-approved)
Hitachi Cable, Ltd.
Serial
Communications
Unit
Remote device
Actual Wiring Example
SG signal wires
Bundle the SG wires.
Aluminum foil
XM2S-0911-E
Pin
Signal
Shell
Shield
Signal
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.
SD
RD
RS
CS
SG
FG
FG
RD
SD
CS
RS
SG
FG
Содержание CJ1W-SCU22
Страница 192: ...4 Using Protocol Macros 4 56 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494...
Страница 250: ...6 No protocol Mode 6 22 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494...
Страница 460: ...A Standard System Protocol R 126 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494...
Страница 473: ...Index 1 CJ series Serial Communications Units Operation Manual for NJ series CPU Unit W494 I Index...