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Each of the entries and exits equips with a controller which controls the gate automatically and sends signals through RS-485 bus to central control room showing the change of available spots. Here¡¦s the problem: Most computers do not have RS-485 interface. Even the IPC may have only one RS-485 port. If we want to receive those signals sent through RS-485 buses simultaneously, we have to use four IPCs. ICP DAS provides a better choice: use one VXC multi-port serial card instead of four IPCs! With VXC multi-port serial cards, the central computer could expand more RS-232/485 ports. For example, one VXC-144U has 4 RS-485 ports, and the signals from the 2 entries and 2 exists of the parking structure are all under control. VXC cards are always the best choice when more RS-232/485 ports are needed! |
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