Addressing the AP1 and AP2 LEDs
You can address the AP1 and AP2 LEDs on the device using the file node.
- Add a file node from the storage category to the workspace.
- Double-click the file node to open the Edit file node dialogue.
- In the Filename text box, enter the device file of the desired LED. Choose from:
- AP1 (green): /sys/class/leds/ucg:green:ap1/brightness
- AP1 (red): /sys/class/leds/ucg:red:ap1/brightness
- AP2 (green): /sys/class/leds/ucg:green:ap2/brightness
- AP2 (red): /sys/class/leds/ucg:red:ap2/brightness
- Disable the Add newline (\n) to each payload? check box.
- Click Done to apply your changes.
- Connect the input of the file node to the node whose messages trigger the writing operation.

The connected node must output values of the type Number in the value range 0 ... 255.
- Value 0 switches off the LED.
- Values 1 ... 255 switch on the LED.