Drive the OnAirScreen ON AIR LED from ProppFrexx

ProppFrexx ONAIR can turn OnAirScreen LED1 (factory label ON AIR) from a mixer-channel event (fader start / channel ON) via EXEC_SEND_HTTP_GET.

This is not the current-title howto. Titles: Show the current ProppFrexx title on OnAirScreen.

API reference: OnAirScreen API / UDP / HTTP / MQTT
Mixer GPI on a Raspberry Pi (no playout in between): User Manual (GPIO)
ProppFrexx: Control-Commands (mixer events, EXEC_SEND_HTTP_GET), HTTP GET from a fader

Signal What it is Use for LED1?
Mixer channel ON / OnFaderStart Mic or channel live on the desk (or ProppFrexx mixer strip) Yes — this is the studio lamp
Playlist playing / OnTrackPlay A file started No — that is the title path
Channel Target (default) Example
HTTP Port 8010 http://OAS-IP:8010/?cmd=LED1:ON
UDP Port 3310 LED1:ON

Same pattern for off: LED1:OFF. Commands are GET only.

On Windows test with oas_send.exe from the OnAirScreen license:

oas_send.exe --ip 192.168.23.5 "LED1:ON"
oas_send.exe --ip 192.168.23.5 "LED1:OFF"

If OnAirScreen runs on the same PC, use 127.0.0.1. Firewall: TCP 8010.

General settings → Events/Commands (GPIO/Remoting). On the mixer channel that is the mic / on-air source, assign:

  • Channel ON or OnFaderStart (pressed / fader open):
EXEC_SEND_HTTP_GET http://OAS-IP:8010/?cmd=LED1:ON
  • Channel OFF or fader closed / OnFaderStart released:
EXEC_SEND_HTTP_GET http://OAS-IP:8010/?cmd=LED1:OFF

Omit username/password in EXEC_SEND_HTTP_GET — OnAirScreen does not use HTTP auth. Forum: EXEC_SEND_HTTP_GET

Event names match the Control-Commands list (mixer-channel events such as OnFaderStart). Use the event that tracks desk live, not OnTrackPlay.

A hardware fader-start (GamePort, Velleman, IO-Warrior, Livewire+, Ember+) maps the same way: GPIO message mapping to the two EXEC_SEND_HTTP_GET commands above (pressed = ON, released = OFF). Test the mapping in the GPIO monitor first so ON is the closed contact, not the open one.

  • EXEC_SEND_HTTP_POST — OnAirScreen commands are GET only.
  • EXEC_SEND_TCP — OnAirScreen has no TCP command port.
  • Raspberry Pi with a desk contact: GPIO in the User Manual is shorter than going through ProppFrexx.
  • Questions: Contact
  • onairscreen/proppfrexx-led-en.txt
  • Last modified: 27.09.2026 01:36
  • by 127.0.0.1