VERFAHREN ZUM ERKENNEN VON BITPARALLEL VORLIEGENDEN ZEICHEN

1410395 Digital exchanges SIEMENS AG 10 May 1973 [2 June 1972] 22331/73 Heading H4P In a programme controlled exchange system in which signals on a plurality of line terminals are each assigned to effect the conversion of dialled characters, to one channel cell in a channel store of a character handling unit; in which characters are entered in bit-parallel fashion, such as is disclosed in Application No. 17751/73 an additional item of address information may be entered in a channel cell assigned to a particular connection line, the additional item is evaluated as a character recognition criterion and after being decoded serves to cause read out of a specific zone of a central character store in which are stored characters to be recognized. The characters in the channel cell which contains the respective additional item and signals in the zone of the character store read out by the additional item are passed to a comparator device. In the case of a positive comparison, a signal is issued to the programme store for evaluation. The additional address information may contain a first part which is conducted to a group number decoder and a second part conducted to a character number decoder, wherein as a result of the address determined by means of the decoding of the first part, a first specific zone within the character store containing the relevant individual character or a second specific zone within the character store containing the relevant character group is addressed and as a result of the address determined by decoding the second part, the relevant individual character or group is read out. In the modified arrangement it is not necessary for an entire character or character group to be stored but only the addresses for the character or group in the channel store. The character or group may be loaded by means of the programme or for example, manually. Further the character recognition means are relieved of load. In Fig. 1, all units co-operate with the central store SP through peripheral section MA which has incoming registers WER, BR, MLR and outgoing WAR, ADR. Registers WER, BR pass command data to control section USt data necessary for conversion. Polarity changes arriving via input lines may require to be intermediately stored in PWER before storage in a channel cell and processing by USt. Information to SP may be through transfer register MTR and word output register WAR, the addressing of individual zones being effected under control of counters B