Polara APS Button Stuck In 2-Flash (Troubleshooting)

Use this article for Polara iNav or iNS APS buttons that are stuck with their LED indicator in a 2-Flash repeating pattern. This diagnostic flash pattern may be seen in both 2 and 3-wire applications.

Applies to the following APS:

  • iNS2/iDS2 (all variants)
  • iNS3/iDS3 (all variants)
  • iN2 (all variants)
  • iN3 (all variants)

Applies to the following Control Units:

  • iCCU-S/S2
  • iCCU-C/C2
  • iPHCU3S
  • iPHCU3W

Understanding the Symptoms (general)

All Polara i-series APS buttons in the same generation share the same firmware file, regardless of being a 2 or 3-wire model. Since 2-wire model buttons can also be used in 3-wire applications, the firmware determines the mode of operation shortly after bootup. It does this by checking for a voltage on the DATA terminal in relation to the GND terminal (green terminal block). If no DATA voltage is detected, the firmware assumes it is a 2-wire application and begins searching for the iCCU, even if no iCCU is present.

Jump to 2-Wire Applications

Jump to 3-Wire Applications

Gather the following before troubleshooting:

  • Control unit model (iCCU-S2, iCCU-C2, iPHCU3S, etc.)
  • Button model (iNS2, iNS3, iDS2, etc.)
  • Wiring mode in use (2-wire, 3-wire)
  • Number of buttons affected (one, some, or all)
  • When the symptom started (new install, after a firmware update, after a replacement, intermittently)
  • Whether a system reboot has already been attempted

Understanding the Symptoms (2-Wire Applications Only)

2-Flash (two red LED flashes, repeating):

The button is powered up but cannot communicate with the control unit (iCCU). This is not a pedestrian call - it is a communication fault indicator. The button has not been placed out of service by the control unit; it is waiting to pair with it.

Constant Call and 2-Flash:

  • These two symptoms sometimes occur together. A button stuck in 2-flash will not generate a call on its own, but the iCCU will on its behalf in some cases
    • An iCCU will create a constant call if a button has both been configured on Phase Setup and later enters the 2-flash state. This is a failsafe of the iCCU - it does not know what state the button is in, only that the button has been assigned to a phase and the iCCU is no longer able to communicate with it. These previously configured buttons will be highlighted in pink on the Phase Setup menu in the app.
  • This can be caused by a shorted field wiring, interference in the communications band, or a failed button.

Section 1: Button Stuck in 2-Flash

If all buttons are stuck in 2-flash there is most likely an issue with the iCCU (all variants), or the cabinet wiring (iCCU-C/C2 only). If at least some of the buttons are communicating with the iCCU, then the issue will be either the button itself, field wiring, or interference in the communications band used by the iCCU.

Step 1 - Check firmware compatibility

  • Confirm the iCCU and button firmware versions are compatible
  • A firmware mismatch between the control unit and button can prevent pairing
  • If firmware is up to date, proceed to next step

See Firmware Release Notes for details:

Release Notes for iNavigator Firmware

Release Notes for iNS/iDS Firmware

Release Notes for iCCU Firmware

Step 2 - Perform a control unit reboot

  • Power-cycle the iCCU and allow the system to fully restart before re-testing
  • If button returns to 2-flash after reboot and waiting 4-5 minutes for calibration, proceed to next step

Step 3 - Change the Communications Channel of the iCCU

  • Under Advanced Comms Settings, try a different comms channel
  • Default from the factory is Channel B
    • Try Channel A next
      • Log into the iCCU directly or a working/communicating button to make the change
      • Give the system 4-5 minutes to find all the buttons
    • If no improvement, try Channel C
      • Give the system 4-5 minutes to find all the buttons
  • See article Advanced Comm. Setting Calibration Explained

Step 3 - Isolate the button

  • Bring the button physically closer to the iCCU (or test with a known-good button at the same location)
    • A button connected on a short pair of wire to the iN2-ICB at the cabinet is expected to find the iCCU in any band (assuming updated FW)
    • If a known-good button pairs successfully: the original button is likely faulty
    • If a known-good button also fails to pair at the same location: the issue is likely with the environment (interference, wiring), assuming all other steps have been tried
      • Contact Technical Support

Understanding the Symptoms (3-Wire Applications Only)

2-Flash (two red LED flashes, repeating):

The button is powered up but did not detect a DATA line voltage within the time window allowed by firmware. After this time window is passed, the button will no longer check for this voltage on this powerup

Check and verify presence of DATA line voltage, then reboot button.

DATA Voltage:

  • 1.3VDC during Don't Walk interval
  • 2.1VDC during Walk interval
  • 1.3VDC/0VDC alternating during Clearance interval

If DATA voltage is not present, check iPHCU3 wiring.

iPHCU3S Wiring

See 3-Wire Troubleshooting Guide PDF or the PSC Article for more info.

When to Contact Technical Support

Contact Polara Technical Support if:

  • All troubleshooting steps above have been completed without resolution
  • The symptom occurs intermittently or returns after reboots
Did this answer your question? Thanks for the feedback There was a problem submitting your feedback. Please try again later.