CONTROL LINE INTERFACE SYSTEM

• Main Authors: TANAKA KENJI, EDA SUSUMU
• Format: Patent
• Language: English
• Published: 28.03.1991
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; SELECTING; TELEPHONIC COMMUNICATION

PURPOSE:To automatically set up switching corresponding to an E & M type (interface type of control lines E, M) by monitoring the on-hook potential of a connected control line and its continuous time to identify its interface type and outputting a corresponding switching signal. CONSTITUTION:The potential of a control line M whose potential level is turned to the low level when a trunk circuit corresponding to the E & M type I is detected as the output of a photocoupler 21 and its continuous time is monitored by a counter 27 and an RS type flip flop circuit 28. When the trunk circuit belongs to the E & M type I, an interface type identification part 25 sends a high level switching signal B to an exclusive OR circuit 30 to invert the logic of an output signal A, so that a signaling circuit of an E & M type V is allowed to correspond similarly to the circuit of the E & M type I. When the trunk circuit corresponding to the E & M type V is connected, the switching signal B is turned to the low level to allow the signaling circuit of the E & M type V to correspond to the E & M type as it is.