| 摘要 |
A method and an arrangement mutually monitor control units. The control units are built up of three program levels. A first level is for executing the control apparatus functions and a second level is provided for monitoring the control apparatus functions and a third level is for monitoring the programs of the second level. A first control unit sends out a selected question to a second control unit which answers the same in the context of a sequence control. The second control unit sends the formed answer back to the first control unit which then, on the basis of a comparison of the formed answer to the expected answer, determines the freedom from fault of the second control unit. Correspondingly, the first control unit is monitored by the second control unit via communication. |
