GB1222794A - Improvements in or relating to centrally controlled exchange systems - Google Patents

Abstract

1,222,794. Automatic exchange systems. SIEMENS A.G. 6 March, 1969 [7 March, 1968], No. 11907/69. Heading H4K. Scanning for line conditions proceeds over subscribers' line circuit groups (such as TG1) and other exchange circuits (such as own and other exchange relay sets HUe and AUe, and operators' relay sets VPl), each group of line circuits and each other exchange circuit having an associated row of a scanning matrix store SpMa, one element of each row indicating the state of the group of line circuits or the state of the other exchange circuit, a row scanner AE1 examining the state elements of each row of the matrix in synchronism with a scan of the corresponding line circuit groups and other circuits, a column scanner AE2 automatically ensuring that the columns containing the state elements are selected during such scanning. The matrix SpMa may consist of a number of planes so as to provide a multi-bit storage capacity for each element of the matrix; ferrite cores being employed as storage elements. The line circuit groups TG have a common intermediate store TZS, comprised of ferrite cores, on which is set up in parallel the states of the individual subscriber lines. An OR-function establishes a group state if any one or more of the lines is in the active state. The corresponding scanning matrix row has an element for each line of the group and an additional element, in column n, to indicate the group state, as last scanned. The first column of each row corresponding to another exchange circuit (Hlle Alle, VPl) records the circuit state. For each scanning position of the row scanner AE1 the state data from the last scan as recorded in the matrix is read out to register ZR2 while the corresponding current data from the circuits themselves is recorded in the register ZR1. A logic circuit ZO determines from a comparison of current and last look data what, if any, action is required by the central control circuit ZeSt, such action being implemented and the matrix store brought up to date before the scanner proceeds to the next row. If the group state data indicates activity requiring attention in a line circuit group, the scanner Ae2 steps over the elements of the intermediate store TZS and the corresponding elements in the associated matrix row so that the states of the individual lines are compared with the last look data in ZO with ZeSt reacting accordingly. The scanner Ae2 has a section 5 said to be employed for route finding.