PURPOSE: To make a bus interface circuit a disable state at the time of inserting and extracting a live-line.
CONSTITUTION: This system is composed of a back wiring board having plural electronic circuit packages 21,..., 2n, a power source supply package 10 for live-line insertion and extraction, a-48V power source bus 30, a signal bus 40 and a +5V power source bus 50. When the electronic circuit package 21 is inserted and extracted, the bus interface circuit 23 1 of the electronic circuit package 21 where a live-line insertion and extraction is performed is made a disable state by the +5V power source supplied from the power source supply package 10 for live-line insertion and extraction, and in this state, a signal terminal 241 is inserted and extracted. Because the insertion and extraction of the signal terminal is performed by making the bus interface circuit of the electronic circuit package for which the live-line insertion and extraction is performed by the power source from the DC-DC converter of the power source supply package for live-line insertion and extraction an bus isolation state when the electronic circuit package is inserted and extracted, the live-line insertion and extraction which does not exert adverse influence on other packages for which bus connections are performed becomes possible.
KABURAGI TATSUYUKI
YASHIRO ZENICHI
AOYANAGI HIROSHI
NIPPON TELEGRAPH & TELEPHONE
| JPH03194613A | 1991-08-26 | |||
| JPH02125314A | 1990-05-14 | |||
| JPH04130912A | 1992-05-01 | |||
| JPH0322118A | 1991-01-30 | |||
| JPH02273818A | 1990-11-08 |