The SAP-612 Source Assign Panel independently assigns each of 12 users station strings to any of six (6) channels. All users assigned to a common channel can intercommunicate and exchange call signals. Up to three (3) TW power supplies (such as the PS-20) may be conveniently connected to the SAP-612 to distribute power to the intercom stations. Switchable 200U line terminations are built into the SAP-612 for proper line termination. The SAP-612 has two (2) balanced, transformer isolated program inputs. Program 1 is permanently assigned to channel 5, and Program 2 is permanently assigned to channel 6.