Code Switching Center

Code Switching Center 

an aggregate of apparatus and switching equipment used for retransmission of telegrams through code switching systems. Each receiving (input) communications channel of a code switching center is connected to the apparatus desk of a code register, which is equipped with a reperforator, a transmitter, a direction selector and an automatic switching device. The apparatus desk is used for reception of telegrams from the transmitting center, their transfer onto the punched tape of the reperforator, and their retransmission into outgoing communications channels by means of the transmitter. The direction selector decodes the routing index received by the code register and, with the aid of an automatic switching device, selects the direction required to route the telegrams to their point of destination. If there are no free channels in the required direction, the switching device stores the telegrams in the “wait” or “hold” positions. Each transmitting (outgoing) communications channel of the center is equipped with a load equalizer, a transmission monitoring desk, a telegraph apparatus, and a numbering device. The transmission monitoring desk is used to produce printed copies of telegrams transmitted through outgoing channels and, when required, for service calls over the telegraph apparatus to and from the center receiving the telegrams. The load equalizer “levels” the load (smooths out irregularities) in the outgoing channel for a given direction. If the outgoing channel is busy, telegrams are automatically routed from the transmitter of the apparatus desk of the code register to the load equalizer and are stored on the punched tape of the reperforator. When an outgoing channel becomes free, telegrams stored in the loop of punched tape are automatically routed to the free channel through the transmitter, the load equalizer, and the automatic switching device. A check of the accuracy of telegrams transmitted through an outgoing communications channel is performed by the telegraph apparatus on the transmission monitoring desk. The total capacity of each code switching system operating in some communication centers of the USSR is 130 directions, each of which has one to ten communications channels. The speed of telegraph transmission is 50–75 bauds.

V. V. NOVIKOV