Overview of DNP3

DNP3 is a communication standard used mainly by the electricity and water utilities. DNP3 is a client/server protocol operating over a number of different communication media. It supports both polling and unsolicited data exchange.

A DNP3 network has Devices, Object Groups and Variations.

• A Device is physical field device such as an RTU (Remote Telemetry Unit) or IED (Intelligent Electronic Device). A Device is identified on a network by its IP Address and its Link Address.
• Each Device has one or more Object Groups. An Object Group (also referred to as a Group or Object) is an array of data points of similar types, for example analog inputs. The Group types are listed in the DNP3 specification. Each Group is referenced by a unique group number that is specific to the data type. For example, Group 1 is Binary Inputs (BI).
• Variations are a specific range of formats in which the data can be presented in each Group. For example, analog inputs can be a 32 bit integer with flag, a 16 bit integer with no flags, etc.

 PcVue's DNP3 configuration is accessed from the Application Explorer - Project.Communication.Data acquisition.DNP3.

 PcVue communicates with a DNP3 network using TCP/IP. It is the client and the field devices are servers. By default, polling is used only to collect the initial state of servers, and for a background integrity check. Normal data collection uses unsolicited data exchange.

The supported Groups and Variations are listed in the topic DNP3 implementation table.