Overview; Protocols - GE 750 Manual

GE
Grid Solutions
750/760 Feeder Management Relay
Chapter 1: Overview

Protocols

Overview

750/760 FEEDER MANAGEMENT RELAY – COMMUNICATIONS GUIDE
Overview
The 750/760 Feeder Management Relay communicates with other computerized
equipment such as programmable logic controllers, personal computers, or plant master
computers using either the AEG Modicon Modbus protocol or the Harris Distributed
Network Protocol (DNP), Version 3.0. Following are some general notes:
• The 750/760 relay always act as slave devices meaning that they never initiate
communications; they only listen and respond to requests issued by a master
computer.
• For Modbus, a subset of the Remote Terminal Unit (RTU) format of the protocol is
supported which allows extensive monitoring, programming and control functions
using read and write register commands.
• For DNP, the functionality is restricted to monitoring of essential relay data and control
of important relay functions. A complete description of the services available via DNP
may be found in the section DNP 3.0 Device Profile Document on page 5 - 1.
DNP is a complex protocol. As a consequence, it is not possible within the scope of this
manual to provide a description of the protocol's operation in anything approaching the
detail required to understand how to use it to communicate with the relay. It is strongly
recommended that interested users contact the DNP Users Group at
to obtain further information:
Members of the DNP Users Group are eligible to receive complete descriptions of all
aspects of the protocol. The Users Group also operates a website (http://www.dnp.org)
where technical information and support is available.
http://www.dnp.org
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