Steps to prepare a PLC elevator program - Database & Sql Blog Articles

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1 System design According to the determination of elevator drag and control and other special requirements, according to the unit and individual conditions, calculate the I / O points and select the PC model specifications, and design the circuit schematic and installation wiring diagram.
2 Design the plc ladder program using PLC as the elevator process electrical control of the intermediate process control. After the circuit schematic diagram and the installation wiring diagram design are completed, the PLC ladder program corresponding to the circuit schematic diagram must also be designed and drawn. The ladder program is PLC. The logic control diagram of various soft and hard relays, its logic control mode is similar to the logic control circuit diagram between intermediate process control relays, so it is one of the important links in the design of PLC control electrical system. When designing the ladder program, it should be connected to the PLC manual manual to understand the PLC I/O interface allocation, combination arrangement and code, various soft relays, data area, channel code, common rules and code number.
The ladder design should generally follow the following rules:
(1) The normally open and normally closed contacts of the I/O point and various internal soft relays can be reused many times.
(2) The coil of the soft relay cannot be directly connected to the busbar on the left, and there should be a transition point.
(3) There can be no more contacts on the right side of the soft relay.
(4) In a set of ladder diagrams, coils of the same code cannot be repeated. (with SET, RST instructions)
(5) The input and output points of the PLC can be used as soft relays.
3. After the infusion program ladder is programmed, it must be infused into the PLC's memory to run. Now that everyone has a computer, we can use the programming software to program the ladder diagram. After connecting the computer to the PLC with a dedicated cable, we can write the program to the PLC.
4. After the simulation running program is poured into the PLC, the simulation operation must be performed first. The method can simulate various states of the input terminal by means of wiring, and watch whether the output signal meets the design requirements.