| 摘要 |
In a multipoint control system such as may be used for controlling lifting jacks for lifting whole railway cars at a time, a remote controller 24 is provided in a hand-held remote control unit. Local controllers 21 are provided associated with jacks 25. Each local controller 21 is an intelligent controller and has a plug and socket arrangement to which the remote controller 24 may be attached. In such a way, the remote controller 24 may be plugged in at any part of the network to control and synchronise operations of all of the jacks 25. Local controllers are all interlinked by a serial data link network which cuts down dramatically on the wiring required. The system is fail safe so that if communication between any of the elements should break down or if any element malfunctions, the system will automatically bring itself to a halt. |
