DNP3

DNP3 ( Distributed Network Protocol) is an official communication standard for telecontrol (see also remote operation ). The protocol is used as a general transmission protocol between control systems and substations.

The messages are typically transmitted over serial links (ITU-T V.24 (EIA -232) / ITU-T V.28 (EIA -422) ). In order to take account of current developments, has been defined retrospectively DNP3 over LAN / WAN. This variation of the Protocol ( the telegrams remained unchanged, only the medium was changed) transmits the messages over the Internet Protocol TCP / IP or UDP / IP.

The DNP3 telecontrol protocol is standardized by the DNP Users Group and developed. The DNP Users Group consists of manufacturers and users of devices with this remote control protocol.

Compared with other remote protocols is still the existence of acceptance procedures emphasize tested with the help of the deployments or can officially be certified by the DNP3 Users Group.

History

The protocol was originally developed by Harris (later, now GE Harris GE Energy ) V3.00 developed and defined under the name of DNP, then passed to the development and care 1993, the DNP Users Group. The original standard is defined in the Basic Documents 4. The DNP Users Group brings However, annual Technical Bulletins of specific items and further developments of the standard out. What stage builds a DNP3 implementation in a device or control system, is documented by appending the date to the log name. So, for example, DNP3 DNP3, 1999 or 2004.

Structure of the Protocol

  • Data Link Layer: link layer for reliable transmission of telegrams
  • Transport Layer: Split in and joining segments in fragment of the Application Layer
  • Application Layer: Receives fragment from the remote station, it executes and sends back a response fragment

User

The DNP3 protocol can be found in many devices from different manufacturers. Well-known manufacturers are:

Distributed control system RS-422
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