DNP3 Outstation Configuration in SEL RTAC
Key Takeaway
How to configure the RTAC as a DNP3 outstation to serve aggregated substation data to SCADA masters — data point mapping, event classes, unsolicited responses, and Secure Authentication.
Quick Answer
The RTAC presents aggregated substation data to the SCADA master (Geo SCADA, Ignition) as a single DNP3 outstation. The SCADA master polls one RTAC address instead of each relay individually.
Data Mapping
- Binary Inputs — Protection status, breaker state, alarms
- Analog Inputs — Metering (IA, IB, IC, VA, VB, VC, MW, MVAR, frequency)
- Counters — Energy accumulators (kWh, MVARh)
- Binary Outputs — Remote trip, breaker control, settings group switch
- Analog Outputs — Remote setpoints
Event Classes
Class 1: trips, alarms, breaker operations. Class 2: metering changes. Class 3: status, informational.
Secure Authentication
DNP3 SAv5 (HMAC-SHA256) for authenticated control commands — required for NERC CIP at BES substations. See DNP3 SA guide.
Frequently Asked Questions
As a single DNP3 outstation. The SCADA master polls one RTAC address to get all relay data, rather than polling each relay individually.
Cryptographic message authentication using HMAC-SHA256 preventing unauthorized commands. Required for NERC CIP at BES substations.