The Model 862 System Interconnect interfaces with the Model 802 Master Stations and other external systems, and equipment. Typically, Model 802 Master Stations access communications circuits which include: conference-line and central matrix type intercom systems, paging systems, telephone lines and two-way radios. The Model 862 System Interconnect enables the connection of up to twelve Model 802 type intercom channels; and up to twelve standard ‘TW” intercom system channels. The Model 802 Master Stations plug into the Model 862 System Interconnect.