Skip to main content

Configure shutdown via remote power switch

This method relies on a time-delay relay that uses the UPS's physical I/O signal to trigger the IPC's remote power button.

Requirements​

  • UPS with dry contact output to signal on battery state or power failure
  • UPS with a powered output to provide supply voltage to the time-relay in case of a power failure
  • Time-delay relay that supports Single shot leading edge with control input (Ws) or Single shot leading edge voltage controlled (Wu)
  • IPC with remote power switch interface
  • IPC BIOS configured to automatically power-on on power restore as described here

Wiring and relay configuration​

To successfully trigger the shutdown:

  • Wire the relay output to the remote power switch of the IPC, so that the relay closes the circuit of the remote power switch when activated.
  • Wire the dry contact output of the UPS to the control contact of the relay, so when the UPS signal goes high, it activates the control contact of the relay.

Adjust your relay, so it functions as a single shot leading edge with control input or voltage input. This means when it first receives a signal via the control input or the supply voltage is applied, it sends out a single, momentary pulse. The pulse duration is configured on the time-delay relay. Afterwards, the relay opens again, which replicates a normal press of the power button.

Set the duration of the impulse to not exceed 200ms. This is usually done with a screwdriver on the front of the time-delay relay. Consult your time-delay relay manual for setting the delay properly.

warning

Verify the voltage supplied by the UPS pwr output is compatible with the time-delay relay coil voltage (typically 12VDC or 24VDC).

Configure UPS​

To trigger the shutdown signal, configure the UPS to either close the dry contact circuit upon power failure or provides supply voltage to the time-delay relay. Depending on your UPS model, this may be the default behavior or require configuration. For more details, refer to your UPS model's documentation.

You can also configure a delay for triggering the shutdown signal, so the IPC is not powered down during a short power glitch. The duration of the delay depends on your UPS capacity. Ensure that you have enough capacity left on the UPS to safely shut down after your configured delay.

You need to be aware that if power is restored during the IPC shutdown process, it won't automatically restart. In such cases, ensure the UPS is configured to power-cycle the IPC's outlet after utility power is restored.

Further, configure the UPS to shutdown after the IPC is fully powered off (a duration no longer then 90 seconds) and to automatically restore power to the IPC once utility power is restored.

Shutdown sequence​

The timing is critical to ensure the OS shuts down before the battery dies.

  1. UPS Power Loss: Utility power fails, and the UPS switches to battery.
  2. UPS powers the relay/ closes the dry contact: The UPS is configured to close its dry-contact I/O output, sending a continuous signal to the time-delay relay as long as it is on battery.
  3. Power Button Emulation (The Pulse): Once the control signal is received or power is provided by the UPS, the relay briefly closes its output for a momentary pulse.
  4. IPC Graceful Shutdown: The pulse simulates the power button press. Which triggers a graceful shutdown of Intrinsic OS.
  5. UPS shutdown: After the IPC has shut down, the UPS either powers off the outlet connected to the IPC or shuts down itself. This is required to guarantee that the IPC will power on again once utility power is restored.

Verification and testing​

  1. Unplug the UPS from the power.
  2. Check if the IPC has properly shut down. You can verify this if no activity LEDs are flashing.
  3. Verify that the UPS also removed power from the outlet of the IPC or has shut down itself.
  4. Apply power to the UPS
  5. Verify that the IPC started as planned and you can start your solution again.