🚀 go-pugleaf

I do some concert production work in my spare time, and I have a large 
task ahead of me in about 12 days ... The gig we are putting on requires 
a choir of around 200 people.. Now the stage manager and the asst. stage
manager
will not be able to molly coddle these people, and there aren't going to be
enough stage hands to `herd' them into the right place at the right time...
I thought that maybe a system like the following would be of use, but I can't
figure out how to implement it... 

Stage manager has a jiffy box that has 8 lit pushbutton switches, with a socket
for a cannon microphone lead in the side of it. Each station has a cannon in
and a cannon out socket, and a couple of hi intensity LED's. Each station has a
hard-set id #. When the stage manager presses the button on the master, the 
correct station lights up. The stations would be daisy chained together, with
the master at the head of the link.

_________              Room1                   Room2            etc, etc
| MASTER|
--------- <---------> +--------+
                      | Slave1 |
                      +--------+ <---------> +--------+
                                             | Slave2 |
                                             +--------+ <-- etc etc..
When button 1 is selected, ONLY slave1's LED's comes on. When button 2 is 
selected, slave2's LED's come on. Slave1 doesn't need to be selected for Slave2
to light up. 

Power supply is anything up to 18V at the master. Cannon lead has 3 wires, so 
I thought +ve, -ve, and signal could be handled on the one mic lead. The signal
could be a binary signal (?) with bits set for each station. 

Am I barking up the wrong tree? is this possible? Apart from very basic stuff,
I have very little experience here (I'm just the computer graphics bod, the
electronic stuff I'll hand to someone else)  Any pointers to adaptable circuits
or ideas would be really appreciated.. Our normal techs are unavailable so I'm
in it up to my eyes!!!!

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