The full form of DNP3 is Distributed Network Protocol. It is a set of communication protocols implemented between parts in the process automation systems. The Distributed Network Protocol is mainly used by water and electric companies; this system is not usually used in other industries. DPN3 was developed for communication purposes between different types of control equipments and data acquisition. It has an imperative role in the SCADA (supervisory control and data acquisition) system. This protocol is utilized by SCADA control centers also known as Master Stations, IEDs (Intelligent Electronic Devices) and RTUs (Remote Terminal units). It is mostly used for the communication in between a control center and IEDs or RTUs.
The design of this protocol is very reliable, but its design did not entirely secure it from hackers or other malevolent elements that could disturb the control system and disable the critical infrastructure. Third parties are generally given access by the smart grid application. This application assumes access by third parties to the same network. A lot of work has been put into add authentications which will help in securing the DNP3 protocol.
DPN3 is recommended as a set of best practices for using the modern SCADA Master-IED / RTU communication links. Though this protocol is a little more expensive than older ones like Modbus, it does provide more efficient, practical, and interoperable features. It provides error checking, multiplexing, data fragmentation, prioritization, etc. Its transport function and application layer are suitable for SCADA applications.
This protocol is efficient, sturdy, secure, and compatible. With changing times and changing needs of industrial applications, DPN3 is reinventing itself over and over again. This perhaps may also put light on the fact that SCADA concepts are not as simple as they may appear. The goal of compatibility is very difficult to achieve because more and more issues emerge with each passing day.