Patent GB-992654-A (GB)
Title: Electrical recording system for telecommunication calls
IPC: H04M15/26
Filed: 1962-09-14
Abstract: 992,654. Automatic exchange systems. STANDARD TELEPHONES & CABLES Ltd. Sept. 14, 1962 [Sept. 15, 1961], No. 35187/62. Heading H4K. In a ticketing system for an automatic or semi-automatic exchange, wherein a plurality of sources are successively scanned in order to derive therefrom information relating to calls utilizing said sources, each source has associated therewith a section of a store in which the stage of the call e.g. calling, dialling &c. and information relating to the call e.g. calling and called parties' numbers are recorded and a common control circuit which examines at each scan the stage which the call has reached in order that further operations and information in respect of the call may be performed and recorded, there being a common recording apparatus to which all the information relevant to ticketing the call is transferred at the termination of the call. As described, the abovementioned sources are the cord circuits of an operator's position which are successively scanned whereby information set-up on the operator's keyboard and metering pulses incoming at regular time intervals to each position are transferred to a store comprising a plurality of magnetic cores for each cord circuit, the contents of these cores being passed to a punched-tape printer of full-page teleprinter at the end of a call. Setting up a call from an operator's position. When an operator has reached the telephone numbers of the calling and called subscribers she depresses her keys co, co<SP>1</SP> and dr so that the control circuit CL is seized when an electronic scanner DA reaches her position and the particular cord circuit involved thereat. Timing pulses dt0 to dt9 from a timing circuit DT are thereby passed to CL whereby at time dt0 an electronic reader LS is set to a position O with consequent setting of a column selector SC to position O. The magnetic cores pertaining to the cord circuits are contained in a store MG which has seven plates pq 1 to sq 7 each carrying a plurality of ferrite cores. Each cord circuit is allotted one of the rows of cores lig 0 to lig n occurring on each plate, the allotted rows in each plate being linked by common vertical wires vt so as to form a plurality of columns col 0 to col m for each cord circuit, information being recorded in the columns col 1 to col m in the form of a 2 out of 5 code. Col 0 (binary coded) acts as a sequence switch and the above mentioned setting of SC to position 0 causes col 0 to be selected whereby the contents of its cores can be read out when a suitable pulse is applied to wire lec by CL during the time It 1. The reading which in this case is 0 is passed as a binary code to a register RL and is then transmitted at time dt 2 via AND gate pt 1 to the reader LS and thence via decoder DCS to CL. The latter at time dt 6 sets LS to position 1 whereby during time dt 7 a sequence writer IS may also be set to position 1. At time dt 8, CL restores LS and hence SC to position 0 (thereby seizing the sequence switch, col 0) and IS, via wires fl 17 and fl 3, causes the cores of col 0 to be set to position 1 when a " write order " is sent by CL on wire ins during time dt 9. Consequently when the sequence switch col 0 is next read, the control circuit ascertains that the calling subscriber's number is about to be set-up on the operator's keyboard tch 0 to tch 9 but until one of these keys has been depressed col 0 is maintained in position 1. However when a key is operated whereby the first digit of the caller's number is recorded as a 2 out of 5 code in register RC, the control circuit at time dt 3 sets LS and hence SC to position 1 and at dt 4 causes the contents of RC to be recorded on the cores of col 1. During the times dt 6 to dt 9, col 0 is set to position 2 as outlined above. When the scanner finds key tch released and no further digit in RC, col 0 is set to position 3 whereby the second digit may be recorded. This procedure is repeated until all the (eight) digits of the caller have been entered in the store and the sequence switch is in position 16. The operator releases dv and operates de whereby a similar procedure in respect of the called party's (14 digit) number occurs, leaving col 0 in position 44 and the cores of columns col 1 to col 22 set. When the call is established, a contact db closes and the sequence switch is set to position 45. Metering.-Pulses from a master clock are fed into pulse lengthener IMP (Fig. 6, not shown) at 10 second intervals whereby corresponding pulses, each of which lasts for the duration of one scanning cycle (a maximum of 12 msecs. for 40 cord circuits), are produced on lead fl 4. Consequently if, when the cord circuit is scanned, a pulse is present on fl 4, CL causes col 23 to be read-out at time dt 4 whereby an entry is made in register RL and maintains scanner DA on this cord circuit during six successive " scans " of timer DT. Similarly columns 24 and 25 are read during the next two " scans " by DT, the readings being passed to sections dz and un and col 0 is set to position 48. In the next " scan " at time dt 4, CL causes the reading in LD to be increased by I and at time dt 5, the reading in section cn is transferred to col 23. In the next two " scans " col 24 and 25 are similarly rewritten and the sequence switch is finally reset to position 45, the scanner DA then being restarted. Release.-This is indicated by the closing of a contact fn and the opening of contact db and at the end of the next succeeding meter pulse col 0 is stepped to position 51 instead of being reset to position 45. When the punched tape printer PF becomes free it informs the control circuit accordingly on wire dis so that during the time dt 4 of the next scan the first digit of the caller's number is read from the store MG and recorded in RL. At time dt 5 it is transferred to another register R1 and then via a transcoder (2 out of 5 code to telegraph code) to the printer, the sequence switch subsequently being set to position 52. An inhibiting potential bt is applied to CL until the digit is recorded on the printer, removal of bt allowing the next digit to be read out and so on. A space is provided on the tape between the calling and called parties' numbers and between these and the number of metering pulses, by a signal from CL on wire pag, the sequence switch being finally set to position 79. The time of disconnection is recorded on the tape from a clock HG and the sequence switch is finally reset to position 0. If the calling subscriber required immediate notification of the charge for his call, the operator (at the beginning of the call) depresses a key cr which causes the necessary code to be written into an auxiliary column of the store whereby at the end of the call a teleprinter TE is additionally associated with the store. Since TE, in general, cannot operate as fast as PF, a transfer memory is included for storing the information temporarily as it is read from the columns of the store. Checking and erasing.-Control circuits CT1 and CT2 ensure that information in registers RC and RL is stored as a two out of five code, the presence of more or less than the 2 operative conditions initiating an alarm. If key er is operated, destructive read-out from store MG takes place and the sequence switch is reset to position 0. Display of calling and called parties numbers during a call. The operator operates her key al whereby when the sequence switch is next in position 50 (at the end of a metering pulse) it is stepped to position 51 and the stored words in columns col 1 to col 22 are successively and non-destructively passed via register RL to a visual display panel LP2. If a further metering pulse should occur whilst this process is in progress, the pulse is retarded (Fig. 8, not shown) so that as soon as the sequence switch is restored to position 45, it may be recorded. Reference has been directed by the Comptroller to Specifications 746,666 and 786,721.