Patent GB-1401522-A (GB)
Title: Data gathering apparatus
IPC: H04M3/36
Filed: 1972-06-27
Abstract: 1401522 Automatic exchange systems; analogue-to-digital conversion WESTERN ELECTRIC CO Inc 27 June 1972 [28 June 1971] 30042/72 Headings H4K and H3H An arrangement for collecting data relating to the usage of a plurality of lines comprises a plurality of terminals, a store with corresponding storage locations, means to scan the terminals repeatedly, means to compare the usage state of each terminal scanned with the state of that terminal on the last scan and as read from storage, and means responsive to the comparisons to accumulate data, relating to the number of usages or the percentage time of use of each terminal, jointly between two data words in the storage location associated with that terminal, the two data words also storing respectively usage data compiled during a current and a proceeding sequence of scans. In the preferred form the invention provides a portable apparatus capable of supervising n lines or groups of lines and to count seizures for use or measure percentage of time in use of each of those terminals, it being possible to individually select the type of supervision to be performed at each terminal. The apparatus includes a recirculating shift register 260 comprising 2 n + 1 storage locations 261 and one storage location 262, each location storing a data word. The location 262 is an access register into which and from which data can be fed in parallel form over lines 266 and 268 respectively. The data words comprise n pairs followed by two synchronizing words. At the beginning of each period of operation a check word generator 281 enters the two synchronizing words into the register and during each subsequent scan, at the appropriate point of the scan as given by a signal on a lead CK from the scan control counter 140, a comparator 282 compares the word in 262 with the check word generated by 281 and in the event of a mismatch causes via a lead ICR incremental shifting of the register 260 until the synchronizing words are found. The two data words of each pair comprise a send word and an add word. The send words arrive in the access register 262 first (being immediately followed by the add word). One bit of each word of a pair comprise together two last look bits which are used to count the number of successive scans of the associated terminal that that terminal is in the active condition, the condition being required to persist for three scans before it is used to update the associated add word. These bits are read out over lines LL1 and LL2 when a send word is in register 262 and the associated add word is in the right most location 261 and entered in a last look register 130. If the corresponding line being scanned is in the active condition the content of the last look register is incremented via a gate 121. If that line returns to the idle condition the last look register is reset via 123. When due to a line being active on three successive scans the count in the last look register reaches three an AND gate 131 responds triggering a pulse generator 132 and blocking gate 121, maintaining the count at three until the line returns to the idle condition. Depending on the type of supervision required for the line being scanned the scanning control counter 140 enables via jumpering 155 one or other of two gates 156 or 158. If gate 156 is enabled a flip-flop 166 is set for each line usage that persists for more than three scans. If gate 158 is enabled a flip-flop 168 is set when a line usage persists for three scans, and the last look register is simultaneously reset such that if the usage persists the flip-flop 168 is set for each three scans. Flip-flop 166 is for counting the number of times the line is used while the flip-flop 168 is used to measure the percentage time of use of the line. Each time a flip-flop is enabled it increments via a line INC the add word at that time in a +1 adder 250. This is effected during the time in which the add word is in register 262. The time in which the send word is in 262 is used to transmit the send word via transmit buffer 290 and translator 292 to an output circuit 298 if transmission is required, the first summing cycle of each data gathering period being used for rearranging the data store 260 to convert add words of the previous period into send words for the new period making the data previously accumulated available for transmission. The apparatus can be fabricated from integrated circuits.