need to be defined. Because the china car elevator manufacturers door lock relay X36 is not closed, the elevator cannot run. The floor signal generation and elimination module mainly reads the floor information by the PLC's comparison instruction and addition and subtraction instructions and stores the memory signal in the corresponding intermediate relay until the floor changes and displays the position of the floor with a seven-segment digital tube.0, according to the requirements of the program [3],

contrast In the input and output allocation table of the PLC in the program design, give the corresponding input signals and observe whether there are expected outputs. Figure 3 Elevator floor position display decoding ladder diagram Ladder diagram simulation of elevator operation process The software simulation to study the elevator operation process is to use Mitsubishi PLC's simulation debugging software GXDeveloper7. The input signal X is set artificially according to the operating law of the elevator, and a corresponding output will be in the output signal Y. X34 is an upper limit travel switch.

The program ladder diagram is shown in Figure 3. The simulation results are shown in Figure 4 (the code with yellow shaded I / O in the simulation results in Figure 4 is represented by a small square). This kind of debugging is the easiest to find some potential problems that are not easy to find at first [4, 5]. In the simulation results, when X is a yellow shade, it indicates an input action, that is, the corresponding input indicator in the PLC is on; when Y is a yellow shade, it indicates that the elevator has an output signal, that is, the output indicator in the PLC is on.

The data register D0 is the number of floors during the operation of the elevator. It is installed on the sixth floor (top floor). Take one of the links as an example to introduce below. When the elevator runs to the first floor, D0 is set to '1'.Elevator control system software can be roughly divided into: elevator door opening and closing and protection and fault display module, floor signal generation and elimination and digital tube display module, outbound signal generation and elimination and display module, car interior signal generation and elimination and