GE Industrial Solutions POWER LEADER ModBus Monitor - Manual (Page 66)

POWER LEADER Modbus Monitor
Glossary
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Glossary
The following are definitions of some of the terms used in this document.
commnet – A GE proprietary network communications standard.
DCS (Distributed Control System) – A group of systems including building automation and status monitoring
systems.
Generic device – A user-defined device type whose register map is entered from scratch or copied from that of an
existing tightly integrated device (TID). Generic device types do not support events or special handling registers.
Hybrid device – A user-defined device type whose register map is copied from that of an existing tightly integrated
device (TID), including event handling and any special handling registers, then customized like a generic device.
Modbus master – The device acting as master to the other devices (slaves) on the RS-485 network. Only the master
may initiate communications; all other devices may communicate only in response to a query from the master.
With regard to the POWER LEADER Modbus Monitor, the master is either a host computer running PMCS
software or a second Modbus Monitor.
Modbus RTU (Remote Terminal Unit) – An open, industry-standard, high-performance network communications
protocol developed by Modicon/AEG Schneider Automation.
Modbus segment – A single RS-485 network connected to one of the Monitor’s two RS-485 ports, labeled Segment
A and Segment B, respectively. No more than two Modbus Monitors are permitted on a single Modbus segment.
A Modbus segment must be properly terminated at each end with a 1/2 watt, 120 ohm resistor.
Modbus-compatible device – Any device equipped with a Modbus RTU communications port.
Monitor – GE POWER LEADER Modbus Monitor.
PMCS – GE’s Power Management Control System software. The Modbus Monitor is compatible with PMCS
version 5.1 or greater.
POWER LEADER – The GE family of comprehensive power management devices and system software used to
minimize downtime and overall power cost.
RS-485/EIA485 – A physical standard for multi-drop, high-speed, noise-tolerant communications over a twisted
pair network; often used with the Modbus RTU protocol.
SCADA (Supervisory Control And Data Acquisition) – A group of systems including power management control
systems.
Segment – see Modbus Segment.
Tightly integrated device – Any of the device types whose register map has been pre-configured in the Monitor.
These devices are listed in Table 1.