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King's Tech Crew

What is OSC, and how do I use it?

OSC (Open Show Control) is a system that, in simple terms, allows you to control the light desk through QLabs through writing commands. Luckily, OSC has already been set-up beforehand, so you won’t have to touch any network related settings. Using it is relatively simple, and can be done as so:

  • Using the template: If you think a show might need OSC, make sure that you press “create file with template”, and click on the OSC template. This will make sure everything network related is initialised, and means that any issues you find when trying to use it should hopefully not be related to the settings.
  • Creating a network cue: On QLabs 5 (the version every show should be using), the network cue is designated by a snowflake symbol. Press this to create a network cue in the timeline.
  • Selecting the right patch setting: Click on the newly created network cue, press the settings tab, and change the patch to OSC Message.
  • Write the script to fire the lighting cue: In the text found underneath the patch setting, write out the following template without the speech marks: “/eos/cue/cue_number/fire”. Then communicate with the light department to find out what the cue number is for the lighting cue they are trying to fire. Replace cue_ number with this, so for example if I wanted to fire cue 742 on the lighting desk, the script would be /eos/cue/742/fire. Edit the pre-wait as required to ensure it is timed correctly, and wait for the green light from the lighting department to test that OSC is working correctly. Once you have done this, you are finished!
    • OSC is usually used during dance shows, and they are used ALOT. If you are not comfortable with OSC, make sure to ask for regular checks with the lighting department, as it is quite easy to use but also quite easy to mess up with. Timing is key, so ensure you take it slow and time every cue to the correct times, especially if linked to a previous sound file.
    • The video below shows an example of how OSC cues are written and timed, taken from IUKS 2026.
    • (this is still not working currently)