Patent GB-925708-A (GB)
Title: Improvements in or relating to arrangements for receiving signals capable of assuming a finite number of values
IPC: H04L13/08
Filed: 1959-12-14
Abstract: 925,708. Code telegraphy. PHILIPS ELECTRICAL INDUSTRIES Ltd. Dec. 14, 1959 [Dec. 17, 1958], No. 42431/59. Class 40 (3). An arrangement for the reception of signals, which may assume a limited number (up to two or three) of values, fed to the input terminals of the arrangement in which the values of the incoming signals are recorded at fixed writing instants in memory elements, whilst the values recorded in the memory elements are transferred in a cyclic order of succession at reading- out instants lying between the writing instants to a logistic member of the arrangement in which at least two memory elements correspond to each input terminal of the arrangement at which the instantaneous value of this signal is written in cyclic order of succession at writing instants in these memory elements, which elements are read parallel at the reading-out instants corresponding to this signal so that if at least r reading-out instants lie between each pair of successive writing instants and if the number of memory elements intended for values of incoming signals is s the arrangement is suitable for the reception of at least rs signals, whilst the writing instants can be divided into periods of s writing instants, each instant of a period corresponding to a given memory element of each group of s memory elements associated with an incoming signal whilst the reading-cut instants can be divided into periods of at least rs reading-out instants, each instant of such a period corresponding to a given signal. In the arrangement described for 7-unit telegraph signals, the signals received on each of twenty-one lines 101 ... 121 are fed via an associated gate P101 ... P121 to a column individual to a line and comprising 25 magnetic cores of which the cores 1 ... 7 of each column are primarily concerned with the reception and storage of the elements of a signal. The gates are pulsed seven times during the period (T) of a signal element from a clock pulse generator 53 which also provides sequential pulses from terminals 92 ... 98 spaced at intervals of T/7. Each of the connecting members from the terminals 92 ... 98 is threaded through twenty-one cores or rings disposed in seven groups of three appropriate to three columns in different rows 1 ... 7 of the core matrix. With the arrangement shown, it is demonstrated algebraically that in a period T the twenty-one signal elements in the lines 101 ... 121 are stored on the twenty-one columns 31 . . . 51 of storage members and that during a period of T a group of associated columns such as for example 31, 32 and 33, or 40, 41 and 42 or 49, 50 and 51 have stored the equivalent of three signal elementsseven storage elements in the columnar direction being allocated to a signal element. The successive groups of three columns are operated at intervals of T/7 to store for a period of T three signal elements. During the period of T/7 following the storage of these elements on three columns three reading pulses are provided in succession to pass the conditions of the storage members to a logistic member 90 which employs circuits to examine the pulses received from the members of the twenty-one columns with a view to the detection of the start element and stop element, the provision of a stop element or the suppression of a false start element. Functions and operations of the logistic member 90.-The member 90 has twenty-five inputs passed from the rows 1 ... 25 of storage members at the reading instants # K  and twentythree outputs permitting the writing of information in the rows 8 ... 25 of the upper matrix and the rows 26 . . . 30 of the second matrix. Of the rows 8 ... 14 a " 1 " written in row 8 of a column designates that the centres of the signal elements of that column correspond to a ring in row 1, whilst a " 1 " written in row 9 indicates that the centres of the signal elements correspond to a ring in row 2 and so on with a " 1 " in row 14 of a column indicating element centres correspond to a ring in row 7. A " 1 " in rows 15, 16 or 17 of a column indicates that the preceding reading of the column terminated with, respectively, one, two or three digits " 1." Rows 18 ... 24, indicate which signal element of a code combination has been read during the preceding reading process and a " 1 " in row 18 meaning that the start element has been read, whilst a " 1 " in row 24 means that a stop element has been detected or its existence presumed for a column so that the next signal element received as a " 1 " on three or more sequential rings of that column is assumed to be the start element. A " 1 " recorded in row 25 indicates that a start element is to be expected or is to be found for that column. The registration of a " 1 " in rows 19 ... 23 pertaining to a column is written as a " 1 " in the ring of the corresponding row 26 ... 30 of that column so that a " 1 " in row 30 indicates that five significant elements have been read and is operative to assign the following interval to the stop element, even if it is not actually detected. The various functional operations to be automatically performed by the logistic member 90 are symbolically indicated in Fig. 5 (not shown) and are effected by gating circuits comprising normal coincidence gates, or cocking gates as described in Specification 925,706.