GE Industrial Solutions POWER LEADER PMCS Network Architecture Guide - Manual (Page 50)

Power Management Control System
Chapter 3 – Network Wiring and Construction
40
You must never connect a single commnet segment to the
Modbus Concentrator at more than one point or to more
than one port on the Modbus Concentrator.
Figure 28 represents the correct wiring scheme for a
commnet segment – linear, one IED to the next,
connected to the concentrator at one port only.
Figure 29 through Figure 32 show various incorrect wiring
schemes – commnet segments that are ‘looped’ and
nonlinear. Avoid these wiring situations as they will cause
communication errors.
Shield Ground
commnet
IED
g
P O W E R L E A D E R
M odbus Concentrator
- + Shld - +Shld - +Shld - + Shld
Commnet Connections
Commnet Connections
commnet
IED
commnet
IED
commnet
IED
Figure 28. Commnet shield grounding wired correctly.
g
P O W E R LE A D E R
M odbus Concentrator
- + Shld - +Shld - +Shld - + Shld
Commnet Connections
Commnet Connections
X
or
X
commnet
IED
commnet
IED
commnet
IED
commnet
IED
Figure 29. Incorrect wiring. Looping on one Modbus
Concentrator commnet port.
g
P O W E R LE A D E R
M odbus Concentrator
- + Shld - +Shld - +Shld - + Shld
Commnet Connections
Commnet Connections
X
or
X
commnet
IED
commnet
IED
commnet
IED
commnet
IED
Figure 30. Incorrect wiring. Looping to two Modbus
Concentrator commnet ports.
To
Modbus
Concentrator POWER
LEADER
Junction/Outlet Box
Commnet
Segment X
or
X
commnet
IED
commnet
IED
commnet
IED
commnet
IED
Figure 31. Incorrect wiring. Looping on segment
connected to Junction Box.
To
Modbus
Concentrator
POWER
LEADER
Repeater
Commnet
Segment X
or
X
commnet
IED
commnet
IED
commnet
IED
commnet
IED
In
Out
Figure 32. Incorrect wiring. Looping on segment
connected to POWER LEADER Repeater.