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Section 2
DNP3 overview
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DNP3 is a communication protocol used between components in process automation
systems. Its main use is in utilities such as electric and water companies. Usage in
other industries is not common, although technically possible. Specifically, it was
developed to facilitate communications between various types of data acquisition and
control equipment. It plays a crucial role in SCADA systems, where it is used by
SCADA master stations (aka Control Centers), RTUs, and IEDs.
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Figure 2:
DNP3 communication schematic representation
1
SCADA master station / control center
2
External control points
3
Communication links (radio, microwave, spread-spectrum, twisted-pair, fibre-optics, dial-up, leased
line)
4
Remote substation (station computer and IED)
2.1
DNP3 standard
AMU0600507 v14
The DNP3 protocol was developed by Westronic based on the early versions of the
IEC 60870-5 standard telecontrol protocol specifications. DNP is now governed by
IEEE Std 1815-2012 IEEE Standard for Electric Power Systems Communications -
Distributed Network Protocol (DNP3)
.
The protocol is based on the EPA, a simplified model of the ISO/OSI model. It
specifies the data link layer, the application layer and a transport pseudo-layer. To
1MRK 511 391-UUS A
Section 2
DNP3 overview
670 series 2.2 ANSI
11
Communication protocol manual