Programmable Logic Controller of Passenger Elevator
With the continuous development of urban construction, the number of high-rise buildings has been on the rise, and passenger elevators have been widely used in the national economy and in life. Elevator as a high-rise buildings in the vertical transport of vehicles has become and people's daily lives are inseparable. In fact the passenger elevator is based on external call signal and its own control laws and other operations, and the call is random, the passenger elevator is actually a man-machine interactive control system, simply using sequential control or logic control can not meet the control requirements, therefore , Elevator control system using random logic control. At present, the passenger elevator control generally adopts two methods.
One is to use the microcomputer as the signal control unit to complete the collection of the elevator signal, the setting of the operating status and functions, and the automatic dispatch and set-selection operation function of the elevator. The drag control is controlled by Inverter to complete; The second control method with a programmable logic controller (PLC) to replace the computer to achieve signal set control. In terms of control and performance, these two methods are not much different.
PLC (Programmable Logic Controller), as an industrial control microcomputer, is widely used in industrial production due to its advantages of easy programming and simple operation, especially its high reliability. It applies large-scale integrated circuits, micro-computer technology and communications technology development results, and gradually formed with a variety of advantages and micro, medium, large, large and other specifications of the range of products used in the control system from the relay to the monitoring computer Between many areas of control.