I recent got a job at a start up company as a systems admin, and knew that I would be programming phones but did not expect to be getting involved with the loudspeaker system. I am not a telecom person so I need some help

We have a bogen PCM2000 loudspeaker system, and executives want to have a buzzer for shift changes, breaks, and lunches. Total of 15 per day. If we add a Talk-back-module we can get 8. So maybe 2 modules? still waiting on the vendor for that..

Since its a startup company they are very tight on money. I was researching if we could use a "Background Music" input to do this. We have electrical engineers on site that said they could rig a timer with a tone output if I can find a way to interface it with the loudspeaker.

Could this be an easier shortcut? I was looking at #2 on this link: https://www.bogen.com/support/drawings/pdfs/PCM2000_Bkgd_Music.pdf

and it looked like it would be pretty simple to wire our timer, and instead of putting it to a speaker, put it to the Background music source.

Sound about right?