| 摘要 |
The proposed dispersed system for monitoring process variables contains a central computer (15) with a modem (14), which is installed in the control station room, and monitoring subsystems (1). Each monitoring subsystem contains process parameter transducers (2), a unit (3) for communication with the transducers, and a microprocessor control unit (7). The microprocessor control unit contains a modem (12), a nonvolatile memory unit (8), a timer (10), and additionally, a displaying unit (9) and a communication line interface (11). The unit (3) for communication with the transducers contains an interface (4) for the transducers with current output signal, an interface (5) for the transducers with pulse output signal, and a data bus interface (6). The communication line interface (11) is connected to the modem (12) of the microprocessor control unit. The modems of the monitoring subsystems are connected to the modem (14) of the central computer (15) via a communication line (13).
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