So I know this is WAY off topic, but you guys rock and are great at coming up with outside-the-box ideas, so I thought I'd hit you up and see what you have to say. And for those of you who aren't into the lingo, an andon is just a fancy word for "signal".

I run outbound shipping for an Amazon warehouse and I'm trying to come up with a good andon system. So far, I haven't found anything that meets all my requirements, which are fairly specific.

Goal: Have a mechanism in each trailer for a loader to signal an andon responder when the loader discovers a defect.

Requirements:
- The andon itself needs to be either highly visible or trigger a mobile receiver. Sound isn’t an option.
- Ideally, I’d like a pager-like device the andon responder can keep with him that displays which dock door needs help.
- Switches to trigger the andon need to be battery powered and work wirelessly.
- Switches need to be able to mount on conveyors going into trailers.
- Switches need multiple channels to allow identification of which of the 20+ doors needs a response.


Note: The dock area is about 150 yards long with 20 dock doors and if this works, we will likely expand the system to twice that many doors.

Thanks!