Sel 751A, Instruction Manual

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Date Code 20100129 Instruction Manual SEL-751A Relay
Appendix D
DNP3 Communications
Overview
The SEL-751A Transformer Protection Relay provides a Distributed Network
Protocol Version 3.0 (DNP3) Level 2 Slave interface for direct serial and
LAN/WAN network connections to the device.
This section covers the following topics:
➤
Introduction to DNP3
➤
DNP3 in the SEL-751A
➤
DNP3 Documentation, Object Tables, and Data Maps
Introduction to DNP3
A Supervisory Control and Data Acquisition (SCADA) manufacturer
developed the first versions of DNP from the lower layers of IEC 60870-5.
Originally designed for use in telecontrol applications, Version 3.0 of the
protocol has also become popular for local substation data collection. DNP3 is
one of the protocols included in the IEEE
®
Recommended Practice for Data
Communication between Remote Terminal Units (RTUs) and Intelligent
Electronic Devices (IEDs) in a Substation.
The DNP Users Group maintains and publishes DNP3 standards. See the DNP
Users Group website, www.dnp.org, for more information on standards,
implementers, and tools for working with DNP3.
DNP3 Specifications
DNP3 is a feature-rich protocol with many ways to accomplish tasks, defined
in a series of specifications known as the Basic 4. A companion specification
called the Subset Definitions simplifies DNP3 implementation by providing
three standard interoperable implementation levels. The levels are listed in
Table D.1 .