DNP3 vs IEC61850: Comprehensive Protocol Comparison Guide

DNP3 and IEC 61850 are two of the most commonly used communication protocols applied in industrial automation and control systems or IACS. Here is an analogy between these two:

DNP3: Distributed Network Protocol

DNP3 was initially formulated for use within the utility sector, particularly in SCADA systems on monitoring and controlling the activity of electrical substations. It was supposed to be robust and reliable over long-distance communication channels, typical in utility environments, allowing support both for serial and IP-based communication.

Characteristics:

• Data transfer is made in priority to serve the critical data in an adequate period
• Supports time-sensitive applications
• It has provisions for the detection of errors and validation of the data
• It can operate in hostile environments with potentially non-reliable communication links

IEC 61850:

It was specifically developed for use by the electric power utility industry to ensure standardization on the communication protocols used in substation automation.

Design is based on a client-server architecture that emphasizes interoperability between devices and vendors in a substation.

Features

• Ethernet-based communication: Uses it to exchange data at high speeds by way of MMS over TCP/IP.
• Specifies object-oriented data models and communication services that make it easier to integrate more devices from different manufacturers into a system
• It supports peer-to-peer communication as well as GOOSE (Generic Object-Oriented Substation Event) messaging for the fast transmission of critical events.
• It includes SNTP for clock synchronisation, in addition to network configuration.

Comparison

Application Focus: DNP3 is mostly used by utility companies for SCADA. IEC 61850 is associated mostly with substation automation and smart grid application.

Communication Medium: Serial and IP-based media can be employed by DNP3; on the other hand, Ethernet-based media are commonly used by IEC 61850.

Data Model: IEC 61850 provides an object-oriented detailed data model to integrate and make devices more interoperable with each other as compared with the traditional approach of DNP3.

Speed and Efficiency: Being based on TCP/IP and Ethernet, IEC 61850 essentially provides higher speed and efficiency in exchanging data than DNP3 does, which was originally designed for slower channels.

Both protocols have high adoption in their domains. DNP3 is more up to date in North America whereas IEC 61850 dominates global application of substation automation.

In summary, the choice between DNP3 and IEC 61850 mainly depends on specific requirements for an application, location of a geographical region as well as existing infrastructure available in industrial automation and power utility sectors.