. The Bell System technical journal . DIRECT CIRCUITS 7 OR 8 DIGITS CONCENTRATOR CIRCUITS 7 OR 8 DIGITS TANDEM TRUNK CIRCUITS NO. 4 TYPE TOLL OFFICE 10 OR n DIGITS. TERMINATINGTOLL CENTER NO. 4 TYPE TOLL OFFICE OR CROSSBAR TANDEMOFFICE Fig. 14 — Use of concentrating equipment in an operator alternate routingarrangement. INTKKTOLL TUl \K CONXENTRATING EQUIPMENT 327 However, it shouhl he lenieinbcrecl that it contains a single controllerwhich could he ciisal)le(l hy compound Irouhle, a condition which couldhe .serious if the concentratin; (Miuipinent were the sole means of handlingtraffic from a
. The Bell System technical journal . DIRECT CIRCUITS 7 OR 8 DIGITS CONCENTRATOR CIRCUITS 7 OR 8 DIGITS TANDEM TRUNK CIRCUITS NO. 4 TYPE TOLL OFFICE 10 OR n DIGITS. TERMINATINGTOLL CENTER NO. 4 TYPE TOLL OFFICE OR CROSSBAR TANDEMOFFICE Fig. 14 — Use of concentrating equipment in an operator alternate routingarrangement. INTKKTOLL TUl \K CONXENTRATING EQUIPMENT 327 However, it shouhl he lenieinbcrecl that it contains a single controllerwhich could he ciisal)le(l hy compound Irouhle, a condition which couldhe .serious if the concentratin; (Miuipinent were the sole means of handlingtraffic from any switchljoard. It is intended that the concentrating equip-ment he used in conjunction with direct intertoll circuits and/or tandemtiunks to a Xo. 4 type toll crossbar switching system. When used withdirect circuits an operator alternate routing system ensues. Referringback to the paragraph which dealt with idle trunk indicating, it is notedthat the direct trunks and tlie concentrator tnuiks form a single groupor subgroup of trunks to a common destination. The direct trunks appealin the multiple at the head end of the group and are followed by co
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
