Patent GB-845219-A (GB)
Title: Improvements in or relating to automatic telecommunication systems
IPC: H04M15/04
Filed: 1957-06-27
Abstract: 845,219. Automatic exchange systems. SIEMENS & HALSKE A.G. June 27, 1957 [June 27, 1956], No. 20346/57. Class 40 (4). In response to the reception of code digits a group of relays operates first to select a route to the desired exchange and then operates again to determine the metering rate. General arrangement, Fig. 1. If a subscriber connected to junction centre KA234 wishes to connect to a subscriber connected with junction centre KA362 he dials a preparatory digit 0 followed by code digits 362. The register-controller at KA234 tests the direct tie-lines QL1 to KA362, and if all are busy the tie-lines QL2 to the main centre HA36. In the latter case the last code digit 2 is sent to set the routing selector in the main centre HA36. If the tielines QL2 are all busy the register controller connects to the associated main centre HA23 and tries QL3-QL5 in succession, sending the last code digit in the case of QL4 and the last two code digits in the case of QL5. In the event of failure the sectional centre ZA2 is brought into use together with QL6 or QL7. For calls to junction centres to which there are no tie lines the routing selections in the originating junction centre are immediately set to the main path HW. When a connection has been established the metering rate is determined. Register - controller, Figs. 3a-3e. Firstchoice route. The first and second code digits are registered by a two-motion selector Wa (not shown), the second and third by another twomotion selector Wb (not shown) after which relay 1U, Fig. 3a, pulls up. Relays 1Y, An, P energize and evaluating multiple AVF1, Fig. 3d, energizes a first routing combination of relays 1E, 3E, in respect of the first group of tie-lines QL1, An and P then falling off. Relays IF, 3E mark contact 10 at the foot of Fig. 3b so that the wiper d of a tapping selector and a parallel routing selector are stepped round until the latter engages outlets to the tie-lines QL1 leading to the junction centre KA362, whereupon relay K operates. If one of these tie-lines is free it is seized. Relay K energizes 2U and releases 1E, 3E and 1U. An and P energize. Relays 3E and 4E now operate in response to connection to evaluating multiple AVF2. Relays An and P restore and 2U energizes D slowly, whereupon 3E and 4E restore and 10U operates, 2U releasing. An and P operate again. The connection to evaluating multiple AVF10 energizes 2E, 3E and 4E so that the tapping selector at the foot of Fig. 3b advances to position 7. An and P restore again, the evaluating relays restore and the wanted subscriber's number is transmitted by means not shown. The register-controller is then released. Second-choice route. If all tie-lines QL1 are busy the routing selector returns an impulse to prevent operation of relay D. Relay 1E therefore energizes and the routing selector tests within the group of tie-lines QL2, leading to main centre HA36, also marked by previously emitted routing digit 10. When relay D operates in this new sequence then relays 9U, 2Y energize followed by An and P. Relay 3E then operates to the evaluating multiple AVF9 to mark contact 2 in the tapping selector. A digit 2 is thus sent over tie line QL2 to the main centre HA36 to set the routing selector there to junction centre KA362. The tapping selector restores and 10U energizes in place of 9U, whereupon the metering rate of the connection is established through evaluating multiple AVF10. Third-choice route. If no tie-line QL2 is free the routing selector again returns an impulse to prevent operation of D, and the routing selector is set by 2E to a free line of the main path HW to the main centre HA23. D then pulls up and 3U replaces 2U. In due course the evaluating relays set by AVF3 set the tapping and routing selectors to contact 5, a digit 5 being simultaneously sent to main centre HA23. 4U then replaces 3U and the routing selector in HA23 tests for a free tie-line QL3 to junction centre KA362. In the register-controller relay D operates slowly and 10U replaces 4U after which AVF10 determines the metering rate of the call. Fourth-choice route. If the tie-lines QL3 are busy operation of D is delayed and HA23 tests tie-lines QL4. When D then operates 9U and 27 operate and evaluating multiple AVF9 ensures that the last code digit 2 is marked on the tapping selector to set the routing selector at HA36 to KA362. AVF10 then determines the metering rate. Fifth-choice route. If the tie-lines QL4 are busy, the routing selector at HA23 tests tie-lines QL5. Relay 8U replaces 4U and evaluating- multiple AVF8 ensures that the second code digit 6 is sent so that sectional centre ZA3 can route the call to HA36. Subsequently 9U replaces 8U so that the last code digit 2 can be sent to route the call from HA36 to KA362. 10U then operates to determine the metering rate. Sixth and seventh choice routes. If the tielines QL5 are busy the call is routed to sectional centre ZA2. 5U replaces 4U and evaluating multiple AVF5 provides the routing digit for testing the lines QL6. 6U then replaces 5U. At response of D relay 9U replaces 6U to send the last code digit to HA36. If tie-lines QL6 are busy then the call is routed over QL7 with 8U, 9U sending the last two code digits. As before, 10U operates finally to determine the metering rate. Modification, Fig. 4. The class value of the call may be determined before the routing digits are sent out. A marking selector Mb is set to terminal, say 4, representing the section wanted by the subscriber. Relays 2F, 1U, An then energize, followed by a combination of relays 1E-4E depending on the evaluating multiple AVF1. An appropriate number of impulses are sent to the meter as wiper Da steps round to the marked contact, at which contact relay P operates, followed by A. Relay An restores so that 3U replaces 1U and 2F, A new combination of relays 1E-4E energizes depending on evaluating multiple AVF3 to mark another terminal in the bank of wiper Da. This wiper steps with a routing selector (not shown) to determine the route. If two routing digits are necessary the marking selector operates twice, IF and 2F energizing after the first and second operations, respectively. 2F energizes 2U and An so that the evaluating relays operate according to the evaluating multiple AVF2, the resulting train of pulses being sent to the meter. Relay A then operates to restore An and 3U replaces 2U to. determine the routing digit through multiple AVF3.