What devices do I need for a system with multiple entrance plates? What is a Concentrator (part no.69MX)?

You must install an 69MX concentrator for systems with multiple entrance plates, if the plates are only for audio communication, then the device is not required. This device balances and distributes the video signal from multiple plates to one or more system monitors. The concentrator is also required when there is an audio/video entrance plate and an 69AM/T video selector.