Patent attributes
Supervisory control of an elevating machine is performed in a remote supervisory center via a general public line. The general public line has multiple networks including a high-speed digital network for transmitting large quantities of information from the elevating machine to the center and a low-communication-cost public network for transmitting a control command from the center to the elevating machine. A network selector selects the high-speed digital network in the case of transmission of a large quantity of information and the low-communication-cost public network in the case of transmission of the control command, and causes the selected network to perform transmission. For security, the control encodes and decodes transmitted information individually for each of the networks, and performs collation and authentication of a specific code, which has been added to the control command at the center, at the elevating machine.
