In the protection relay, it is possible to activate up to five protocol server instances. A function block represents the protocol on the protection relay’s application configuration level. The block is named DNPLPRT1...5, depending on the instance in use. For each connected client, an instance has to be activated by dragging the function block to the configuration in the PCM600 Application Configuration tool.
By default, instance 1 is always instantiated in the protection relay, but needs to be set “On” to be activated. Since the protection relay’s native IEC 61850 data model restricts client limit to five, the protection relay can have only five client connections in total, regardless of the protocols to which the clients belong. This includes the MMS clients and other communication protocol clients.
Protocol instances are identified with numbers 1...5. There are different and unique setting and monitoring parameters for each instance in the HMI menu. Instance numbers can be freely used. However, it is recommended to use the instances in the numerical order. For example, instance 1 is to be used if there is only one client connection and instances 1 and 2 when there are two clients.