PROCESS AND DEVICE FOR THE TRANSMISSION, IN A RELIABLE MANNER AS REGARDS SIGNALLING TECHNIQUES, OF SERIAL DATA BETWEEN RELIABLE COMPUTERS OPERATING PREFERABLY ON TWO CHANNELS BY MEANS OF A TWIN-LOOP BUS SYSTEM

摘要

In normal operation, the two loop buses convey data in opposite directions in parallel and in a redundant manner, one channel of each computer being allotted respectively to one bus by means of active bus couplers. In the event of an anomaly the buses are interrupted cyclically in sections in order to locate the faults, and transverse connections are established with the other respective bus. After the defect has been located, the adjacent sections are transferred continuously to a single-loop structure without redundancy, the faulty section being separated. At the same time, for the control of the two buses, an active control station is planned which hierarchically manages the rights to access to the bus for the other bus sharers who have their own computer, and compares in a cross-manner by means of appropriate monitoring functions, the data circulating in one bus in relation to the transmission data in the other bus and vice-versa. Non-agreement reveals an anomaly which results in switching to the test mode, in which the control station cyclically calls up the sub-stations; activated bus couplers grouped respectively in pairs in bus control units progressively effect breaks and transverse connections, until a non-agreement between the data emitted and data received inside the control station indicates the location of the fault, which leads to switching into the ''FAULT'' mode.