GB1360980A - Data collection systems - Google Patents

Abstract

1360980 Selective signalling MARCONI CO Ltd 26 Oct 1971 [14 Nov 1970] 54325/70 Heading G4H A data collection system includes a tree hierarchy of data junction points, a group of these at one level feeding data to a single one at the next level, each data junction point having a plurality of data input paths and a single data output path and means for adding to data outgoing on the data output path an identifying signal which identifies the input path of that data. A data junction point may have two input paths, each providing a data bit to a respective bi-stable, the states of the bi-stables being set in parallel into a 4-bit shift register, preceded by a 0 and a 1 respectively to identify the respective input paths, the shift register then being shifted out to the data output path. If there are three input paths, the third may be identified by the absence of a bit. If there are more than three input paths, multi-bit codes may be used to identify them. The tree hierarchy of such data junction points may be connected between data generating points and a central decoding office, so that a given piece of data passes through a succession of data junction points in turn, with further path-identifying signals being appended at each point, the tree ending with a level having one or more than one junction point connected by a (common) line to the central decoding office. (In the case of more than one, they are scanned in a predetermined order). Application to automatic operation of marshalling yards, and remote reading of domestic electric and gas meters, is mentioned.