A relay contact is available at connection X2.
You can use it to interrupt the power supply of a closed hardware (e.g. RevPi Dio, Wireless Router…).
The relay contact is normally closed. However, you can switch it bitwise in the process image (RevPiLED, bit 6). This could also allow you to set the relay to switch automatically when the watchdog reports an error, for example. How to do this, we explain to you here.