GE Industrial Solutions POWER LEADER PMCS Network Architecture Guide - Manual (Page 76)

Power Management Control System
Appendix C – Special Wiring Considerations
66
This section describes the connections required to wire
the following PMCS IEDs into a Modbus RS-485 network:
• GE Fanuc 90/30 and 90/70 PLC’s with
Communications Coprocessor modules.
• GE Fanuc Micro 90 PLC
• DB9 connections to the Connect Tech RS-485 card
• DB9 connections to the POWER LEADER Ethernet
Gateway
90/30 and 90/70 PLCs
To wire the Communications Coprocessor module of a
PLC 90/30 or PLC 90/70 to an RS-485 network, you will
need two 100-inch lengths of Belden 9271 cable covered
with sleeving and a male DB-25 connector.
The DB-25 connector should have the following jumper
connections made inside the connector.
• Pin 9 to Pin 13
• Pin 21 to Pin 25
• Pin 22 to Pin 23
• Pin 10 to Pin 11
Connect the two cables to the DB-25 connector as follows:
Conductor DB-25 Pin
Cable 1 White 21
Blue 9
Shield 1
Cable 2 White 25
Blue 13
Shield 1
Apply heat-shrink tape or jacket over the connector for
protection.
At the end opposite the connector, strip about 3 inches off
the outer jacket of each cable. Label one cable “RS-485
IN” and the other cable “RS-485 OUT”.
Micro 90 PLC
NOTE: Micro 90 PLCs withfirmware revisions V3.10 and
higher support 2 wire Modbus connections directly – the
conversion from 4 wire to 2 wire is only needed with
earlier versions.
To wire the communications port of a PLC Micro 90 to an
RS-485 network, you will need two 100-inch lengths of
Belden 9271 cable covered with sleeving and a B&B
Electronics 485FWTW (or equivalent) two-to-four wire
converter, a female DB-25 connector, and a male DB-15
connector.
The DB-15 connector should have the following jumper
connections made inside the connector:
• Pin 6 to Pin 15
• Pin 8 to Pin 14
Connect the two cables to the B&B 486FWTW as shown in
Figures C-1 and C-2.
T
120-ohm
term ina ting re sisto r
R S -232to R S -485
C o nverter
. . .
H O S T PC
(R S -232 port)
R S -232to R S -485
C o nverter
S eries 90 M icro
(R TU po rt)
Last dev ice
T
4-w ire cable
2-w ire cable
Figure C-1. RS-485 two-wire Modbus network.
PM C S M o dbus N etw ork
2-w ire R S -485
D ata A (-)
D ata B (+)
S hield
D ata A (-)
D ata B ( +)
S ignal G round
Fram e G ro und
12 V dc +
12 V dc -
6 screw te rm ina ls
3 R D A (-)
16 R D B (+)
2 TD A (-)
14 TD B (+)
7 S ignal G round
1 Fram e G roun d
12 V dc +
12 V dc -
25-pin m ale
D -styl e co nn ecto r
10 R D A (-)
11 R D B (+)
12 S D A (-)
13 S D B (+)
7 S ignal G round
1 S hield
6 R TS A (-)
8 C TS B (+)
14 R TS B (+)
15 C TS A (-)
15-pin fem ale
D -styl e co nn ecto r
B & B 485FW TW
2/4 w ire c o nverter
12 V dc
P o w er
M icro 9 0 R TU P o rt
4-w ire R S -422
Figure C-2. Modbus network and Series 90 Micro RTU
Port Wiring.