AUTOMATIC SWITCHING SYSTEM 



467 



Table I 



tlie called line and for "marking", if idle, the called line control terminal 

 appearance on the reed-diode switches. At the time of tliis test, a voltage 

 ''mark" is applied to the incoming trunk control lead appearance also. 

 As before, these two ''marks" from opposite ends of the switching net- 

 work cause the selection of an idle junctor and in turn the operation of 

 the reed crosspoints in the four switching stages along the selected path. 

 The "marking" voltage is applied to the incoming trunk terminal of 

 the switches through the winchng of a relay which, operating immediately 

 after the crosspoints, causes the release of the incoming receiver and 

 places the switching connection under joint supervision of the called 

 and calling subscribers. The hue cut-off relay whose winding is in series 



TELEPHONE 

 OFF -HOOK 



ORIGINATING 

 RECEIVER 



0.165 SECOND 



TRUNK 

 NUMBER-GROUP 



SWITCHING- 

 NETWORK 

 CONTROL 



OUTWARD 

 ACTUATOR 



TERMINATING 

 RECEIVER 



SUBSCRIBER 

 NUMBER-GROUP 



0.291 



RINGING 

 CONNECTED 



0.380 SECOND 

 J I 



0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 



TIME IN SECONDS 



Fig. 13 — Operating sequence based on average holding times. 



0.45 



