930 



THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1956 



use at the control end, adapted for transmission testing, is presently 

 available only for No. 4 type toll switching offices. 



Fig. 2 is a block schematic of the arrangement for automatic intertoll 

 trunk testing, including transmission tests. In the originating No. 4 toll 

 crossbar oflicc an automatic outgoing intertoll trunk test circuit is used 

 which consists of an automatic outgoing intertoll trunk test frame and 

 one or more associated test connector frames. These frames have been 

 provided in all No. 4 type offices and perform the functions of setting up 



MANUAL (2 MEN) 



NEAR END 

 OFFICE 



FAR END 

 " OFFICE 



If) 4 

 lij 



i3 



CIRCUIT 



OPERATION 



TESTS 



TEST 

 BOARD 



TEST 

 BOARD 



5 

 H 



1 - 



2 -WAY 



TRANSMISSION 



MEASUREMENTS 



■■ 



3.5 



8.0 



MAN MINUTES PER TEST 



SEMI-AUTOMATIC {l MAN) 



TEST 

 BOARD 



103 

 OR 

 102 

 OR 

 104 

 TEST 

 LINE 



(CODE 104 TEST 



INCLUDES 



NOISE CHECK) 



CODE TEST 



/ ' s 



102 104 



a? 0.9 1.8 

 MAN MINUTES PER TEST 



FULLY AUTOMATIC 



Fig. 1 — Time required for manual tests versus semi-automatic and fully auto- 

 matic tests. (1) Average time per test for 52,000 field test measurements in 20 

 offices under normal operating test conditions (includes test preparation, time 

 waiting to be served, testing time, and recording of results). (2) Average time j)er 

 test for test measurements made in rapid sequence during light load period. The 

 semi-automatic code 104 test includes a noise check at the far end only. 



