Driving the Watchdog/User Relay

The EPM-07 and the EPM-15 devices both have an Output Relay, single pole double throw (SPDT), socket and push in plug on their base:

EPM-07

EPM-15

The integral Watchdog/User relay always opens on Watchdog failure of the device and can be driven by your application. For example, it is possible to drive alarm beacons independent of any I/O modules installed:

Watchdog Relay  
Electrical durability
400,000 cycles 2 A 250 Vac resistive
Minimum switching current
10 mA 5 Vdc
Switched voltage range
24 to 250 Vac (47 - 63 Hz)
5 to 125 Vdc
Switched current range
2 A maximum at 24 Vdc or 250 Vac (resistive)
0.4 A maximum at 125 Vdc (resistive)
Snubber
External
Isolation
Between contacts and +24 V Power supply 3000 Vac
Between contacts and ground 3000 Vac
Note - Differences in load current, ambient temperature, load type and switching frequency impacts the number of operations.

To configure the Watchdog/User relay:

  1. Connect your alarm beacon to the Watchdog/User relay socket on the base of your EPM device.

    Note - The EPM device output is a volt free contact.

  2. From the channel required, configure an appropriate Alarm, see Configuring an Alarm for details.

  3. Once the alarm is configured, select Add Job. and configure the Job to trigger the relay.

  4. From the Job, select Add action .

  5. Complete the Action details:

    • Descriptor - Defaults to 'Action n' where 'n' is the next number in sequence from the previous Action. Enter a unique name for this Action to identify it if required (maximum characters 40).

    • Category- From the available list, select Watchdog Relay.

    • Invert - Defaults to Off , select the toggle to change this to an Absent trigger , for example:

      • With Invert Off , the Watchdog Relay is active whenever the alarm is active.

      • With Invert On , the Watchdog Relay is active whenever the alarm or Job is not active.

See Configuring an Alarm, Configuring Jobs and Configuring Actions for details.

Last update March 2026