The principle of elevator floor reversal with up and down speed change switches - News - Global IC Trade Starts Here.

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SMD aluminum electrolytic capacitor

In conventional elevator circuits, the floor sensor is usually used to reverse the floor. In this way, at least one sensor is required for each floor in the hoistway, and the number of input points occupying the plc is large. Since the programming function of the PLC is very rich, it is possible to use the uplink speed change and the down speed change signal to perform the floor flipping, so that only two sensors on the side of the car are needed to realize the flipping and deceleration signals of the elevator floor. Issued, which brings convenience and cost savings to the installation.

The plc programming ladder diagram is shown below (four-layer elevator as an example)

1. When the elevator is going up, whenever the upper speed sensor is inserted into the magnetic isolation plate, M0 has a cycle trigger.

2. M0 pulls in and makes the value in register D200 increase by 1.

3. When the elevator descends, each time the speed change sensor is inserted into the magnetic isolation plate, M1 has a cycle trigger.

4. M1 pulls in and reduces the value in register D200 by 1.

5. When the elevator descends to the lowest level and the forced switch is actuated, the value in D200 is forced to 1.

6. When the elevator goes up to the highest level and the forced switch is actuated, the value in D200 is forced to 4.

(here, 4 layers are taken as an example)

In this way, the actual value in the D200 reflects the actual floor value of the elevator. The D200 is decoded to obtain the first floor when the M501 is closed, the second floor when the M502 is closed, and the third floor when the M502 is closed. It is the 4th floor. At the same time, the elevator deceleration signal is also given when the elevator performs floor reversal.