. Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems . ond selectors run to third selectorswhich are grouped according to thousands. Their banks in turn leadto connectors by hundreds. Incoming trunks from other offices in theexchange terminate on incoming second selectors whose banks aremultipled with the local second selectors. Levels two and three are trunked out to the associated office. Therethey terminate in third selectors for the second and third thousands. The second selectors at whose banks occur the division between 26 AUTOMATIC! TELEPHONY offices m
. Automatic telephony; a comprehensive treatise on automatic and semi-automatic systems . ond selectors run to third selectorswhich are grouped according to thousands. Their banks in turn leadto connectors by hundreds. Incoming trunks from other offices in theexchange terminate on incoming second selectors whose banks aremultipled with the local second selectors. Levels two and three are trunked out to the associated office. Therethey terminate in third selectors for the second and third thousands. The second selectors at whose banks occur the division between 26 AUTOMATIC! TELEPHONY offices may be located anywhere, the question being one of local condi-tions. They may be in one of the two offices, as illustrated. They maybe in a third office. (Fig. 23.) In this case the traffic from the fouroffices at the left divides at office A for the 42-43 thousand office and the45^48 thousand office. When any subscriber dials 4, his first selectortrunks the call to a second selector at A. If now he pulls 2 or 3that selector will trunk the call to the lower office at the right. But if. Fig. 23.—Traffic divided atintermediate office. Fig. 24.—Traffic divided at two intermediate offices. he pulls any digit from 5 to 8 inclusive, that selector will trunkthe call to the upper office. Again, the traffic may be divided at two intermediate offices. () In this case the traffic from offices at the left is most convenientlygathered together and separated at office A while that coming from theoffices at the right can be handled better at office B. The exact routingof inter-office cables is not indicated. First Selectors
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttelephone, bookyear19
