| 摘要 |
1. Two-channel fail-safe microcomputer switching network, in particular for railway security systems, having microcomputers (MC1, MC2) processing the same information in two channels, the data buses (DB1, DB2) of which microcomputers are connected via two coupling circuits (EV1, EV2) to each of two external data buses (DB10, DB20), to which input signal converters (E1, E2) and output signal converters (A1, A2) are connected which are selected with the aid of adresses given via an adress bus (ADB1, ADB2) of the associated microcomputer and can be activated by means of read or write signals (lOR1, lOR2, lOW1, lOW2) given via control lines (ST11, ST12, ST21, ST22) of the respective microcomputer, the two external data buses (DB10, DB20) being activated temporally staggered during the input phases in such a manner that the input signal converters (E1, E2) present in pairs on the two external data buses only become effective after one another with respect to the same information, characterized in that there is provided in each of the two channels between the control lines (ST11, ST12, or ST21, ST22) and the converters (E1, A1 or E2, A2) a control circuit (SG1, SG2), to which and to the respective coupling circuit (EV1 or EV2) in each case there are connected a first and a second address line (AL71, AL81 or AL72, AL82) of the associated address bus (ADB1 or ADB2), in conjunction with a channel-specific identifier ("L", "H), the control line (ST11 or ST21) carrying the read signal (lOR1 or lOR2) being additionally connected to the coupling circuit (EV1 or EV2) of the respective channel in such a manner that, per channel, the external data buses are switched off by the internal data buses (DB10/DB1 ; DB20/DB2) and the control circuit is switched off by the converters (SG1/E1, A1 ; SG2/A2) in the case of one value ("L") of the address bit (2**7) output via the first address line (AL71 or AL72), and in the case of the other value ("H") of this address bit (2**7), upon the presence of read signals (lOR1 or lOR2) by means or equivalence combination of the respective value ("L" or "H"), of the address bit (**8) of the second address line (AL81 or AL82) with the channel-specific identifier ("L" or "H"), an alternating data input takes place from one or the other external data bus (DB10 or DB20) to in each case both internal data buses (DB1, DB2). |
