Samsung 5080 Alarm

I have a discontinued Samsung SHR-5080 8 channel DVR system. I am reinstalling it at my house now, it was at my office. I have a few microphones and 5 Honeywell HD50 dome cameras (non-PTZ) but decent resolution and night vision with motion detection, I think adequate for my application. I have the user manual, but I cant seem to get an understanding of what the Alarm ports are for. Says you can connect a RS-485 device to it. Is this only for PTZ camera controlling? Can I make this system somehow beep in my house if outside motion is detected? I dont think I want to invest in a PTZ camera, since I already have cameras to cover nearly the entire outside of my house. I do have basic electronics skills, and could get a cheap radioshack chirp.