Monitoring power to a controller

Using the PowerMonitorService, a controller provides status monitoring of its AC power and battery level.

You are running Workbench and are connected to a running remote station.
  1. Expand Config > Services > PlatformServices and double-click PowerMonitorService.
    The Power Monitor view opens.
  2. To configure this service, change the Shutdown Delay Time and or alarm source configuration for both types of alarms: low battery level and primary power lost.
    The software provides status monitoring of the following items, via Boolean slots:

    • AC power is monitored by the Primary Power Present slot. This slot reports true when AC power is currently supplied to the controller.

    • Battery level is monitored by the Battery Good slot. This slot reports true if the last test of the NiMH battery was good.

  3. If needed, make a Px binding or link to the these slots
    Because any station’s PlatformServices are dynamically built upon startup, if binding its slots to Px widgets (or linking to other station components), be aware of the following limitations and guidelines:

    • Subscription behavior is unique to a station’s PlatformServices slots in that property values initially load, but do not automatically update. To explicitly refresh such properties, you must invoke the pol” action on the container for those properties.

      For example, if on a Px page you bind a BoundLabel to the PowerMonitorService’s Battery Good slot, it displays true or false, however, this value does not update until you right-click and execute the Poll action, which forces a fresh read.

    • Links from PlatformServices (and child slots) to other station components must use a source ORD’s slot path rather than its handle. After a station restart or host reboot, handle-sourced links may be lost.

      Consider this update limitation before linking PlatformServices slots into other components that provide control logic. Linked slot values may well be outdated shortly after station startup, yet still subscribed and not marked as stale.



    The screen capture shows a link from the RelationSheet of a target component and how to edit the link to use the slot path for source ORD.

    In addition to the read-only status slots, the PowerMonitorService provides related configuration slots, which you typically review at commissioning time. For more details refer to the JACE Niagara 4 Install and Startup Guide.