TRANSMISSION SYSTEM FOR DIGITAL AUDIBLE SIGNAL TONE

摘要

PURPOSE:To realize the digital intermittent audible signal tone transmission system which is turned on and off with the time sharing gate circuit sampled in the intermittent period for readout periodically for the stored pattern in PCM for the continuous tones of various audible signals, and to aviod the increase in the memory capacity of digital telephone exchangers. CONSTITUTION:The PCM pattern of a number of continuous audible signals in the memory unit ROM is periodically read out with the readout control circuit RCTL and latched at FF. The counter CTR produces the intermittent periods T1-TK to the countinuous audible signals fa-fp and feeds them to the gates G1-Gn. The gates G1-Gn gate the intermittent periods T1-TK with the sample clocks C1- Cn. The digital intermittent audible signal tone thus obtained is transmitted to the time slot of the time sharing highway HW via the time sharing multiplex circuit SEL.