THROWDOWN MACHINE FOR TRAFFIC STUDIES 341 



The circuit associated with the gate assigns all calls and markers ac- 

 cording to No. 5 preference arrangements and provides the correct 

 gating action. This preference is set up on cross-connection field located 

 within the position and may be changed to correspond to any desired 

 system arrangement. 



MARKER POSITION 



A photograph of the marker position is shown on Fig. 19. The indi\dd- 

 ual marker units, of which ten are provided, are disposed on the sloping 

 work panel. On the array panel are jack arrays representing the Une 

 hnk frames, the number groups, outgoing sender subgroups and senders, 

 and the marker connectors. Connections to these jacks are made by 

 means of plugs and cords located at the top of each marker unit. 



The call slip for dial tone class of call is shoT\^i inserted in a marker 

 unit on Fig. 20. At the top of the slip, in the type and grig line boxes 

 and opposite t grig and t cgnn, are typical entries as made by the 

 originating operator. The marker operator has also made three time 

 entries. 



The heaw dot at the top edge of the call slip indicates which of the 

 six class keys to turn. The class keys condition the marker circuit to 

 handle each type of call correctly. The hole at the top of the sUp lines 

 up with a jack and is used to store temporarily the line peg (register or 

 incoming trunk peg in the case of other types of call) as received from 

 the gate; it also serves to locate and hold the call slip in the correct 

 position. 



On the lower portion of the shp are spaces corresponding to all marker 

 actions requiring association with other frames or circuits. These spaces 

 line up with lamps on the marker unit which signal when and what 

 action should be taken and indicate whether or not the time should be 

 entered on the call slip. If a delay is encountered at an> point, a check is 

 put in the associated delay block to assist in subsequent computations 

 invohdng the call slip. The left hand row of lamps hghts to indicate 

 when a direct action should be taken and a time written down. For 

 example, when the third lamp from the left hand top lights (opposite 

 LLF cord) the operator places the line link frame cord at the top of the 

 unit in the correct jack in the llf connector array, and writes down 

 current time in the space opposite the lamp. If the llf jack is occupied 

 by another marker, the operator plugs the llf cord in a preference delay 

 jack associated with the line link frame jack and places a check mark 

 in the delay block. 



