| 摘要 |
<p>PURPOSE:To make a complicated timing circuit required for a sequential control unnecessary and to equalize an operation period to that of one stage by providing switch control parts for the 1st, 2nd and 3rd switches independently. CONSTITUTION:Connection to a trunk from a telephone set is sequentially executed through the 1st switch 5, the 1st link 8, the 2nd switch 6, the 2nd link 9 and the 3rd switch 7 in order. The 1st switch 5, the 2nd switch 5 and the 3rd switch 7 are independently controlled by switch control parts 10, 11 and 12, respectively. The control is realized when a CPU16 feeds control information to the switch control part through I/O interface 15. The L-th switch (L=1,2 and 3) consists of a drive system and a channel system; the drive system is composed of a path selection relay coil, XS switch coil and an U/L relay coil, and a channel system consists of LXJpcs. of switch module, which means that Jpcs. of group (block) made of Kpcs. of switch module constituted of contact points.</p> |
