Patent ID: 6965950

Claim:
A signal input and output apparatus for issuing a control signal from a signal processor to the outside by one of a plurality of controllers through a transmission path, and controlling said signal processor by one of said plurality of controllers on the basis of a control signal entered from the outside, comprising: a single transmission path along which a plurality of different types of apparatuses can be connected, each of said different types of apparatuses issuing a different type of control signal and receiving control signals from a corresponding one of said plurality of controllers; and signal discrimination changeover means for discriminating the type of control signal entered through the single transmission path corresponding to one of said different types of apparatuses, generating a discrimination signal, supplying said discrimination signal into the signal processor controller, and selecting one of said plurality of controllers corresponding to said discriminated control signal to control the operation of the signal processor controller; wherein input and output of plural control signals of different types are processed through said single transmission path, said single transmission path supporting two-way communication of said plural control signals, each of said plural control signals having different input and output amplitudes; and wherein discrimination of the type of control signals in said signal discrimination changeover means is carried out on the basis of an amplitude of the control signal at a coupling to said signal discrimination changeover means of the transmission path for an input and output of control signals.