| 摘要 |
PURPOSE:To attain ease of sectioning of a fault by providing a means for displaying on/off state of each signal of a mutual connection circuit with a data terminal equipment, a means for delaying a next numeral request signal to the data terminal equipment for a prescribed time and a means for selecting making the delay means effective or ineffective when a fault takes place in the automatic call function. CONSTITUTION:The titled control unit consists of a display circuit 5 displaying 8 kinds of signals between unit 1 and equipment 2, a circuit 3 retarding a next number request signal being one of the 8 kinds of signals for a prescribed time and a circuit 4 executing a selection for making the delay circuit effect or ineffective. In case of the automatic calling, 8 kinds of signals are transmitted and received according to the procedure between the unit 1 and equipment 2 according to the procedure. In case of normal use, since the delay circuit 4 is not required, the changeover at normal state and maintanance is attained by providing the circuit 4 selecting the ineffective/effective state of the delay circuit 3. If a fault takes place in the automatic call function, the delay circuit 3 is made effective to demarcate a fault between the network control unit and the data terminal equipment by observing the procedure of the transmission/reception of the signal between the network control unit 1 and the data terminal equipment 2. |
