PJ-Link Node

PJLink is a unified standard for operating and controlling projectors.

I came across this library and want to pack it into a handy Node, what shouldn’t be too hard.

But before i start this, i wanted to discuss the pros and cons of PJ-Link.
Because it sounds really well, but i have absolutely no experience with that technique/standard.

so, the questions could be:

  • did anyone use PJ-Link in any conjunction yet?
  • how many devices out there really support PJ-Link?
  • is PJ-Link a reliable solution that can be used for professional applications?
  • last but not least: does anyone here have a PJ-Link enabled projector for testing and debugging purpose? … because i don’t :(


oukay, next time i should search more carefully.

are there anyway some statements?

I just used PJ-Link to open and close the hard shutter on a Panasonic D4000 series projector. Node attached.

It sends the ‘audio and video mute’ and ‘audio and video unmute’ commands. The projector needs to have no password set for this to work.

Note that there is a ‘video mute’ command but the Panasonic will only respond to the ‘audio and video mute’ command.

I’ve found it very reliable for this show. Quick response and easy to automate.

A full Pj-link node could be handy, particularly for asking a projector to switch to a backup input or for some kind of live focus/zoom change. The only issue with focus and zoom is you don’t get any feedback on current position of the lens so you would have to do a lot of rehearsal to make sure it got it every time.

A proper node would also want to implement the authentication if you had a password, and have some kind of interpretation of the response from the projector.

PJLink Shutter.v4p (22.0 kB)

pjlink worked well in our projects, most of them with no password set in the projectors menue. more reliable than the old rs232 interfaces anyway