JPS644152A - Cpu controlled type subscriber line control interface circuit - Google Patents

Abstract

PURPOSE:To easily cope with various subscriber line signal systems by generating a pulse having a width corresponding to a signal from a subscriber line or the like and measuring the pulse width by means of the program control. CONSTITUTION:A subscriber line signal input conversion section 13 converts a DC signal level from a telephone set into a signal level of a CPU section 11 from a telephone set and inputs the result to a CPU 11 via an input line 14. The CPU section 11 uses a program stored in a ROM section 12 to discriminate a sent signal (cut-off or calling or the like) to generate a pulse of a corresponding time width based on the result of discrimination and sent to a carrier device signal output conversion section 16 via an output line 15. The conversion section 16 converts the sent signal to a level suitable for the carrier equipment and gives an output to a common section. Moreover, the signal from a carrier equipment signal input conversion section 17 is processed nearly similarly and outputted to a subscriber line signal output conversion section 20.