PASSENGER TRANSPORT SYSTEM HAVING CENTRAL CONTROL UNIT AND MULTIPLE FIELD DEVICES HAVING AN OPTIMISED FAILURE DETECTION METHOD

摘要

The invention relates to a passenger transport system (1) comprising a central control unit (13), a plurality of field devices (17(a), 17(b), 17(c), 17(d), 17(e)) and a bus system (33) for transferring data between the central control unit (13) and the field devices (17(a), 17(b), 17(c), 17(d), 17(e)). The passenger transport system (1) is configured to carry out a failure detection method, in which: the field devices (17(a), 17(b), 17(c), 17(d), 17(e)) are received in a logically linked manner as in an unbranched chain configuration; the control unit (13) transmits a test telegram to a first field device (17(a)) in the chain configuration via the bus system (33) in order to start a monitoring cycle; during the monitoring cycle, in response to the relevant field device (17(a), 17(b), 17(c), 17(d), 7(e)) receiving a test telegram, each field device (17(a), 17(b), 17(c), 17(d), 7(e)) forwards the test telegram to a next field device (17(b), 17(c), 17(d), 7(e)) in the chain configuration via the bus system (33), until the test telegram reaches a final field device (17(a), 17(b), 17(c), 17(d), 7(e)) in the chain configuration; and, during the monitoring cycle, the control unit (13) monitors a communication between the field devices (17(a), 17(b), 17(c), 17(d), 7(e)) occurring via the bus system (33), in order to detect when a field device (17(a), 17(b), 17(c), 17(d), 7(e)) does not forward the test telegram. A data volume to be transmitted via the bus system (33) during the failure detection method can be significantly reduced in comparison to conventional failure tests on the basis of the proposed serial forwarding of the test telegrams, such that, for example, failures can be recognised more quickly and/or simpler hardware and/or software can be used.