The SCADAPack E rPAC/RTU can support multiple masters. The multi-master feature is a licensed option and can support up to 3 different DNP3 master station addresses in the configuration.
When using DNP3 and the SCADAPack E rPAC/RTU, any DNP3 host may read the current values using point range qualifiers of Class 0 polls. Only the configured master(s) may poll for event data. This can be done via object requests or Class 1,2 or 3 polls.
The SCADAPack E rPAC/RTU stores only one copy of each event in memory regardless of how many masters are configured. An event is only deleted when every enabled master station has confirmed the event (assuming the point was configured for Class 1,2 or 3 for each master). For this reason, it is not recommended to configure a second (or third) master in the rPAc/RTU if the master station does not actually exist. Otherwise, event storage will continue to grow to the maximum allowed by the rPAC/RTU.
The ability to present class data to other master stations may have applications in local HMI stations or for rPAC/RTU’s used for custody transfer. The multi-master feature is NOT used for redundancy to a second master station (with a different DNP3 address) that is not online.
Detailed information and configuration about the SCADAPack E multi-master feature can be found in the SCADAPack E documentation set included with E-Series Utilities.