GE Industrial Solutions POWER LEADER PMCS Network Architecture Guide - Manual (Page 30)

Power Management Control System
Chapter 2 – Network Design
20
achieved with any allowable combination of
Repeaters and IEDs.
6. For ease of wiring, the POWER LEADER
Junction/Outlet Box may be used to create nodes of
commnet IEDs with a common wiring point to be
connected to the Modbus concentrator. The
POWER LEADER Junction/Outlet Box allows the
interconnection of as many as four shielded, twisted-
pair cables to create this common wiring point. This
can be of great help in economizing on wiring and
offering greater flexibility in network design. For
instance, rather than a daisy-chain of the wiring in a
lineup from one meter or trip unit to the next, up to
four IEDs may be wired to the POWER LEADER
Junction Box, which is then connected to the
Modbus Concentrator.
CAUTION: The four-IED-per-segment limit must
be observed at all times. Although the POWER
LEADER Junction Box has terminals to accept
up to 12 commnet lines, do NOT connect more
than four commnet IEDs to a single Junction
Box or Modbus Concentrator commnet segment.
Examples of the use of a POWER LEADER Junction
Box with the Modbus Concentrator are provided in
Figure 19 and Figure 20. Junction Boxes are not
counted as IEDs for purposes of the four IED per
commnet segment limit. Figure 19 is an example of
a Junction Box used to create a node connecting
four commnet IEDs to a Modbus Concentrator.
Figure 20 is an example of a Junction Box with
Repeaters, observing the four IED per segment limit
(the two Repeaters and the Junction Box do not
count as IEDs).
Junction
Box
commnet
IED
to
Modbus
Concentrator
commnet
IED
commnet
IED
commnet
IED
Figure 19. Network illustrating commnet Rule 6.
POWER
LEADER
Repeater
Long-range
commnet segment
POW ER
LEADER
Repeater
Junction
Box
to
Modbus
Concentrator
commnet
IED
commnet
IED commnet
IED
commnet
IED
Figure 20. Network illustrating commnet Rule 6.