System for discovering a critical path in a network

Claim 1

In combination: a network-modelling circuit having a plurality of node elements (Np, Ns) interconnected by link elements (M), the link elements providing with the node elements three categories of lines interconnecting and passing through the node elements, a. a first category forming a Beta chain for conveying signals from node element to node element via respective link elements in a predetermined direction through the network, b. a second category forming a gamma chain adapted to convey signals in a direction opposite to the said predetermined direction, and c. a third category forming an Alpha chain adapted to convey signals in the same direction as the Beta chain and extending through the node elements; OR gates (8) included in the Alpha chain and forming in the network a validation necessary for operation of the corresponding Beta chain; and a control center (201) comprising a clock (202) for supervising a stepwise advance of signals along the Beta chain and for initiating energization of the gamma chain at the end of such advance; the Beta chain comprising in each node element an AND gate (1) to whose inputs (E2) are connected the Beta lines (50) from the several link elements (M) connected to such node element, and said several link elements having associated therewith a circuit (3, 31, 4, 7, 11) adapted to detect and select from such several elements, the first one reached by a Beta signal, or the last one reached by a Beta signal or both the first and last ones reached by a Beta signal, and adapted, in response to such detection, to validate an AND gate (5) on the gamma chain extending through the link element so selected.

Claim 16

A method of detecting loops in a network, comprising the steps of: i. setting up in combination a control center (201) and a network-modelling circuit corresponding to said network; the network-modelling circuit having a plurality of node elements (Np, Ns) interconnected by link elements (M), the link elements providing with the node elements three categories of lines interconnecting and passing through the node elements, a. a first category forming a Beta chain for conveying signals from node element to node element via respective link elements in a predetermined direction through the network, b. a second category forming a gamma chain adapted to convey signals in a direction opposite to the said predetermined direction, and c. a third category forming an Alpha chain adapted to convey signals in the same direction as the Beta chain and extending through the node elements by way of OR gates (8) and forming in the network a validation necessary for operation of the corresponding Beta chain; the control center comprising a clock (202) for supervising a stepwise advance of signals along the Beta chain and for initiating energization of the gamma chain at the end of such advance; and the Beta chain comprising in each node element an AND gate (1) to whose inputs (E2) are connected the Beta lines (50) from the several link elements (M) connected to such node element, and said several link elements (M) having associated therewith a circuit adapted to detect and select from the several link elements, the first one reached by a Beta signal, or the last one reached by a Beta signal or both the first and last ones reached by a Beta signal, and adapted in response to such detection to validate an AND gate (5) on the gamma line extending through the link element so selected; ii. exciting circuit setting signals in one of the chains before any starting of the clock by triggering said one chain from at least one node element of the network and for a time sufficiently long for the trigger signal to progress as far as the end of the chain and to set circuit elements in the network; and iii thereafter interrupting the circuit setting signals and displaying the loops revealed in the network-modelling circuit, and the circuit downstream of the loops.

Claim 17

A method of detecting loops in a network, comprising the steps of: i. setting up in combination a control center (201) and a network-modelling circuit corresponding to said network; the network-modelling circuit having a plurality of node elements (Np, Ns) interconnected by link elements (M), the link elements providing with the node elements three categories of lines interconnecting and passing through the node elements, a. a first category forming a Beta chain for conveying signals from node element to node element via respective link elements in a predetermined direction through the network, b. a second category forming a gamma chain adapted to convey signals in a direction opposite to the said predetermined direction, and c. a third category forming an Alpha chain adapted to convey signals in the same direction as the Beta chain and extending through the node elements by way of OR gates (8) and forming in the network a validation necessary for operation of the corresponding Beta chain; the control center comprising a clock (202) for supervising a stepwise advance of signals along the Beta chain and for initiating energization of the gamma chain at the end of such advance; and the Beta chain comprising in each node element an AND gate (1) to whose inputs (E2) are connected the Beta lines (50) from the several link elements (M) connected to such node element, and said several link elements (M) having associated therewith a circuit adapted to detect and select from the several link elements, the first one reached by a Beta signal, or the last one reached by a Beta signal or both the first and last ones reached by a Beta signal, and adapted in response to such detection to validate an AND gate (5) on the gamma line extending through the link element so selected; ii. exciting circuit setting signals in one of the chains before any starting of the clock by triggering said one chain from at least one node element of the network and for a time sufficiently long for the trigger signal to progress as far as the end of the chain and to set circuit elements in the network; and iii thereafter interrupting the circuit setting signals and displaying the loops revealed in the network-modelling circuit, and the circuit downstream of the loops.