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THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1951 



Now we come to the coding elements themselves. 



Because of the large number of these, optimum design is important. In 

 the illustrations and in most applications the output codes are formed by 

 the coding devices placing marks on the output code marking leads. The 

 output language could be different, of course, and possibly with economy 

 in the translator itself, but the philosophy of using code marking leads in 

 the output end is the same as that just mentioned for the input system. 



CODE POINT 

 SELECTOR 



OUTPUT CODE 

 BUS BAR SYSTEM 

 I I I I 

 I I 



OUTPUT CODE MARKING 

 LEADS OR BUS BARS 



Fig. 10 — Four general methods of output coding in changeable translators. 



The coding methods shown require a multiple of all or part of the output 

 code leads before the coding elements, that is, a bus system. It is the prob- 

 lem of the coding elements to mark the required buses in the various out- 

 put groups without causing false marks on buses not involved by ''back-up" 

 through the connecting network or at least keeping the back-up below 

 levels providing adequate discrimination between wanted and unwanted 

 signals. 



This back-up problem is solved in translators of the Dimond ring, slide 



