1、INTERNATIONAL TELECOMMUNICATION UNION)45G134 2 TELECOMMUNICATIONSTANDARDIZATION SECTOROF ITU4%,%2!0(94%,%2!0(G0G042!.3-)33)/.-!8)-5-G0G0!#%04!“,%G0G0,)-)4&/2G0G04(%G0G0$52!4)/.G0G0/&G0G0).4%22504)/./&G0G04%,%2!0(G0G0#(!%,3G0G0!2)3).&2/-G0G0&!),52%G0G0/&G0G04(%G0G0./2-!,G0G00/7%23500,)%3)45G134G0G0Re
2、commendationG0G02 (Extract from the “LUEG0“OOK)NOTES1 ITU-T Recommendation R.81 was published in Fascicle VII.1 of the Blue Book. This file is an extract from theBlue Book. While the presentation and layout of the text might be slightly different from the Blue Book version, thecontents of the file a
3、re identical to the Blue Book version and copyright conditions remain unchanged (see below).2 In this Recommendation, the expression “Administration” is used for conciseness to indicate both atelecommunication administration and a recognized operating agency. ITU 1988, 1993All rights reserved. No pa
4、rt of this publication may be reproduced or utilized in any form or by any means, electronic ormechanical, including photocopying and microfilm, without permission in writing from the ITU.Fascicle VII.1 - Rec. R.81 1Recommendation R.81Fascicle VII.1 - Rec. R.81MAXIMUM ACCEPTABLE LIMIT FOR THE DURATI
5、ON OF INTERRUPTIONOF TELEGRAPH CHANNELS ARISING FROM FAILUREOF THE NORMAL POWER SUPPLIES(former CCIT Recommendation B.40, 1951)The CCITT,consideringthat in switched telegraph networks a 300-millisecond interruption of the telegraph current would be translatedinto a release of switches, and that the
6、relays controlling the release are arranged to operate in slightly less than 300 ms,unanimously declares the view(1) that it is desirable that no interruption of the telegraph current should occur as a result of failure of a normalpower supply.(2) If, however, it is impracticable to avoid an interruption, then its duration should in no case exceed 150 ms.
