SEL-3555 Real-Time Automation Controller (RTAC)

Unmatched performance for all your automation and control needs

  • Multicore processing handles automation and integration for small and large projects.
  • Powerful real-time operating system ensures deterministic and uninterrupted automation for all critical applications.
  • Integrated web human-machine interface (HMI) with local display port eliminates the need for an additional computer.
  • Robust cybersecurity is engineered throughout the system architecture.
  • Now supports 100,000 tags!


Network Security Device—Make the SEL-3555 Real-Time Automation Controller (RTAC) the secure access point into your substation or plant. Implement Lightweight Directory Access Protocol (LDAP) central authentication and role-based user authentication, project passwords, web upload features, access logs, and secure engineering access via Secure Shell (SSH). Map security tags into SCADA reports for industry-leading integration of security technologies.

SCADA Remote Terminal Unit (RTU)—Quickly design an integrated substation RTU system that includes protocol conversion, SCADA communications, synchrophasors, time synchronization, data management, and custom logic.

Data Concentration—Communicate with any device through built-in client and server protocols. Exchange data through DNP3, Modbus, IEC 60870-5-101/104, LG 8979, SES-92, SEL Fast Messaging, Mirrored Bits communications, and IEEE C37.118 for synchrophasors. Convert data between protocols, perform math and logic functions, and execute output logic for real-time control.

Event Collection—Detect, filter, and collect event data automatically from connected SEL relays. Fault location, fault current, and other data are populated into tags for easy retrieval through SCADA protocols. Automatically collect and archive events through the RTAC with acSELerator Team SEL-5045 Software.

Substation Controller—Create your logic solutions in the embedded IEC 61131 logic engine, which comes standard with every RTAC. Build custom user logic. Access all system tags, including diagnostics, contact I/O, protocol data, and communications statistics, to provide unparalleled control flexibility.

IEC 61850 Integration—Integrate modern intelligent electronic devices (IEDs) into control and automation schemes with IEC 61850 GOOSE and the manufacturing message specification (MMS) client and server.

Operation Supporter/Regulator—Meet or exceed IEEE 1613 and protective relay specifications for harsh environments with the RTAC, which is designed to withstand vibration, electrical surges, fast transients, and extreme temperatures.