Intelligent Roadway Information System
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:
|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:
Fault: Stuck On
Flashing: External(use when an external system can control the beacon)
State is one of the following values:
|State not known due to communication error
|Lights flashing, commanded by IRIS
|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:
- Changing state manually through the user interface
- Deploying or blanking DMS with a remote beacon
- Activating a ramp meter with an advance warning beacon
- With action plans containing beacon actions
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.