Intelligent Roadway Information System


Select View ➔ Message Signs ➔ Beacons menu item

A beacon is a light or set of lights that flashes toward oncoming traffic. Sometimes called flashers or wig-wags, their purpose is to draw attention to a static sign or DMS.

Beacons can be connected to controllers using one of these protocols:

API Resources 🕵️
  • iris/beacon_state (lookup table)
  • iris/api/beacon (primary)
  • iris/api/beacon/{name}
Access Primary Secondary
👁️ View name, location geo_loc
👉 Operate state
💡 Manage message, notes preset
🔧 Configure controller pin, verify_pin, ext_mode


Message is a static text message on the sign.

Notes can be any extra information about the beacon.

Pin is the controller output pin to activate beacon.

Verify Pin is a digital input to sense whether the lights are activated, for beacons which have verify circuitry. For the CBW protocol, it is also an output to energize the verify circuit. Pin and Verify Pin can be the same.

Ext Mode determines the state reported when a verify is detected without being commanded:

State is one of the following values:

State Description
Unknown State not known due to communication error
Dark Not flashing
Flashing Lights flashing, commanded by IRIS
Flashing: External Lights flashing, commanded by external system
Fault: Stuck On Lights flashing, but not commanded
Fault: No Verify Flashing commanded, but not verified

Beacons can be controlled in a few ways:


Whenever a beacon's state changes, a time-stamped record is added to the beacon_event table. These records are purged automatically when older than the value of the beacon_event_purge_days system attribute.