Is the SEL-3354 an RTAC?

No. It is a rugged computing platform. RTAC function required the SEL-3532 conversion kit (discontinued). For new projects choose a current RTAC such as SEL-3350 or SEL-3555.

What replaced the full-rack SEL-3530?

SEL recommends the SEL-3350 for many replacements. The SEL-3530-4 remains the compact midrange RTAC option.

Does the RTAC need external GPS?

IRIG-B from an external GPS clock provides precise time. NTP/SNTP over Ethernet is an alternative depending on accuracy requirements.

SEL RTAC Hardware Platforms — Current Models and Legacy Notes

Quick Answer

Current SEL RTAC choices include SEL-3530-4 (compact midrange), SEL-3350 (computing platform configurable as RTAC), SEL-3555 / SEL-3560S / SEL-3560E (high performance), SEL-3505/3505-3 (compact), and SEL-2240 Axion (modular I/O). The full-rack SEL-3530 is no longer in production. The SEL-3354 is a rugged computer, not an RTAC, unless converted with the discontinued SEL-3532 kit.

SEL-3530-4

1U half-rack / flexible mounting
Midrange protocol gateway and logic controller
Successor form factor for many smaller SEL-3530 applications
Substation EMC rated

SEL-3350 (as RTAC)

Current midrange computing platform that can be ordered/configured as an RTAC
Greater processing, RAM, and SSD than legacy SEL-3530
Optional local display port for HMI on many configurations
Common replacement path when retiring a full-rack SEL-3530

SEL-3555 / SEL-3560S / SEL-3560E

High-performance RTACs for large point counts and fast logic
exe-GUARD allowlist anti-malware
TPM on current 3555-class hardware (e.g., SEL-3555-2)
Optional integrated web HMI with local video port
3560S/E offer 3555-class performance in smaller surface-mount packages

SEL-3505 / SEL-3505-3

Compact, lower-voltage RTACs
Full standard RTAC protocol and logic feature set in a smaller package
Note: graphical web HMI is not available on SEL-3505/3505-3

SEL-2240 Axion

Modular I/O and control platform using the RTAC logic/communications stack
EtherCAT I/O modules for high-speed deterministic I/O
Optional local touchscreen for bay control / HMI use cases

Legacy: SEL-3530 and SEL-3354

SEL-3530 (full rack) — No longer in production; still widely installed. Prefer SEL-3350 or SEL-3530-4 for new purchases.
SEL-3354 — Embedded Automation Computing Platform (EOL), not an RTAC by default. RTAC conversion used the discontinued SEL-3532 kit; SEL recommends upgrading to SEL-3555 rather than converting a 3354.

Time Synchronization

IRIG-B from a GPS clock (e.g., SEL-2407), NTP/SNTP, and on newer platforms PTP where supported. Precise time is critical for event timestamp correlation across relays.

Frequently Asked Questions