The RT9080 E&M Controller contains an RT8000 C.O. controller board mounted piggiback onto an interface board. The C.O controller board provides the regular RT8000 C.O. functions and the interface board provides the 4W E&M interface which is accessible on a DB-15 connector at the rear of the unit.

A ground on the E’ lead (pin 2 of the DB 15 connector) causes the unit to go off hook.

Ring on the line activates the ‘M’ relay, placing a short between pins 1 and 9 (‘M’ lead).

Transmit 4W audio is on pins 4 and 12; level is preset for 0dBm into the line with +7dBm input.

Receive 4W audio is on pins 3 and 10; level is preset to –16dBm with 0dBm from the line.