GE Industrial Solutions POWER LEADER PMCS Network Architecture Guide - Manual (Page 15)

Power Management Control System
Chapter 1 – Introduction
5
1–3 Required Hardware
Several pieces of hardware are required to build a network
based on PMCS. They are the host computer and the
network interface card, each of which is described below.
Once the host computer is operating and its interface card
is installed, it is time to attach the power management
IEDs to the network. These IEDs are described in Section
1–8.
Host Computer
The heart of the PMCS is software running on a host PC.
Regardless of whether the host PC is based on an Ethernet
or Modbus network, its functions include the following:
• Communication management
• Primary user interface
• Data collection, storage, and retrieval
• Event reporting with time and date stamp
• Energy calculations and trending
• Network IED status
• Alarming and reporting
The minimum requirements for the host PC are presented
in GEH-6514, Read This Book First.
The communications interface is the connection between
the host PC and the network of IEDs. Your host will
require either an Ethernet communications card, an RS-
485 communications card, or an RS-232/RS-485 converter.
An Ethernet-based host PC requires an Ethernet network
card. A Modbus-based host PC requires an RS-485
interface card or an RS-232/RS-485 converter. These are
described below.
RS-485 Interface Card or RS-232/RS-485 Converter
The RS-485 interface card provides the interface between
the host PC and the Modbus network and terminates the
network at the host computer. This standard RS-485
interface card provides eight RS-485 ports. PMCS supports
up to 256 RS-485 communication ports. See Sections 2–1,
2–4, and 2–7 for more details on using multiple RS-485
networks with PMCS.
For more modest needs, a single RS-485 network can be
provided by an RS-232/RS-485 converter, a self-contained
IED that converts signals between RS-232 and RS-485. This
IED plugs into the RS-232 port on the back of the host PC
and is less expensive than an RS-485 interface card.
Ethernet Network Card
The Ethernet network card provides the interface between
the host PC and the Ethernet network. With the host
communicating over Ethernet, another interface is
required to communicate with RS-485 networks, where
most power management IEDs reside. (Some recent power
management IEDs, such as the EPM 7700, have built-in
Ethernet capability. Install these devices using standard
Ethernet networking procedures.)
This interface between Ethernet and RS-485 is provided by
the Ethernet Gateway. See Section 1–4 for more
information on Ethernet, and Section 1–1, Figures 2 and
4, for examples of how the Ethernet Gateway is used to
integrate RS-485 networks into the Ethernet network.
1–4 Compatibility & Interconnection with Existing
Ethernet Networks
PMCS and the Ethernet Gateway require TCP/IP to be
installed on the host computer. The drivers for the
TCP/IP protocol are included with Windows 2000 SP2,
which is required to run PMCS, so any customer running
PMCS should have these drivers available.
Consult your LAN personnel or system integrator for
information on integrating PMCS with an existing
Ethernet-based network.
1–5 Operation During Power Outage
PMCS will not lose any data in the event of a power outage;
however, communications will be interrupted until power
is restored.
Should control power to a Modbus Concentrator be lost,
PMCS will be unable to communicate with any commnet
IEDs downstream from the Concentrator until power is
restored. No data will be lost, but communications will be
interrupted.
The same is true of the Ethernet Gateway; as the linchpin
connecting the host to the network of IEDs, if a Gateway
loses control power, the host will be unable to
communicate with any IEDs attached to the Gateway until
power is restored.
You can avoid this situation by providing uninterruptable
power supplies (UPS) to the host computer and by
providing secure control power to the IEDs, either with
UPS systems or battery backups (different IEDs have
different requirements). Refer to individual user guides
for information on control-power requirements.