Most later model Sony camera control units have a DB-25 connector on the rear of the CCU that allows the user to patch in a digital Matrix intercom system via 4-wire connections to the Matrix frame MVX ports. The drawing below shows the 4-wire connections for the ENG and PROD channels. If connecting directly to a Matrix frame declare the ports as "Directs".
The CCU can also be connected to FOR-22s if the 4-wire input / outputs are connected to the DB-9M connectors on the FOR-22 rear panel card. Sony CCUs that use this common 4-wire configuration:
A 4-wire / 2-wire connection diagram is attached below as a PDF.