Energy Management System (EMS) product update – new feature: updated Rectangular Rapid Flashing Beacon (RRFB) flash pattern "RFB"

This article details the "RFB" RRFB flash pattern EMS feature update: when it occurred, the firmware version required, how it works, and more.

Product applicability

The following products are discussed in this article:

  • E Series: R920-E
  • F Series: R920-F
  • G Series: SC315-G

When did this update occur

Starting in late 2020 Q1, all systems above received this update. This includes all replacement Energy Management System (EMS) boards. The new flash pattern will show up as RFB under the flash (FLAS) menu. 

What firmware version is required

This flash pattern is supported starting with firmware version

Theory of operation

Interim Approval 21 (IA-21) specifies that the RRFB flash pattern duration should be 800ms with a total of 75 flashes per minute. To further comply with this requirement, Carmanah has increased the accuracy of our standard RRFB flash pattern setting, which is designated on the EMS user interface as “RFB”. 


New orders for RRFB systems will be pre-programmed for the “RFB” setting. It is important to be aware of the following:

  • For replacement systems (such as for a knockdown) or a replacement EMS, you may need to check the original system or another one at the intersection to verify the flash pattern setting the replacement must match. Please refer to this article here for more information on the different RRFB flash patterns.

  • Systems shipped in 2014 or older may be using a legacy RRFB flash pattern known as “wig-wag," whereas newer systems use the “wig-wag + simultaneous” flash pattern. If you are receiving a replacement system or EMS for one of these crossings, all systems need to be evaluated for a replacement EMS. The legacy “wig-wag” flash pattern is no longer compliant under IA-21. This is covered under IA-21 Section 5f:

    • Existing RRFB units that use the flashing sequence that was specified in the Interim Approval 11 memorandum and a subsequent interpretation (the RRFB indication on the left-hand side emits two slow pulses of light after which the RRFB indication on the right-hand side emits four rapid pulses of light followed by one long pulse of light) should be reprogrammed to the flash pattern specified above in Condition 5b as part of a systematic upgrading process, such as when the units are serviced or when the existing signs are replaced.

When possible, Carmanah will match orders for replacement RRFB controllers to the project's original order configuration so each system at the crossing will look uniform while the flash pattern is active.

See the table below for the estimated time frame of flash pattern changes:

Date Range


System Model


Flash Pattern


September 2014 and older

R920 or SC315

Legacy “wig-wag”: Left-hand side emits two slow pulses then right side emits four rapid pulses followed by one long pulse of light¹

September 2014 –
~Q1 2020

R920 / SC315

E / F / G Series

“wig-wag + simultaneous” (RFB1)

~Q1 2020 and newer

E / F / G Series

Updated “wig-wag + simultaneous” (RFB)

Contact Carmanah if you are unsure what system you have and what parts or settings may be required to be compliant.

¹ All systems at a crossing with this legacy version must be replaced with a new EMS when servicing. This will ensure these systems are updated to the IA-21 flash pattern specification.

The Energy Management System (EMS) is factory programmed and the firmware cannot be updated in the field.