1. For the control system to learn more about the
Before performing the PLC control design, we must first understand the detailed process and control requirements, what control should be taken, which input signal is required, the choice of what input element, which outputs a signal to the PLC for an external load driving is performed by what element; Lane all aspects of the overall process clear linkages; understanding driven mechanically moving parts, the links between elements of the hydraulic, pneumatic or electric, and the moving member performs the respective electric; understanding of the system is fully automatic or semi-automatic control mode, the control process is a continuous operation or single operation cycle, whether manual adjustment request, and the like. Also, pay attention to what amount needs to be monitored, alarm, show the need for fault diagnosis, types of protection required, and so on.
2. Initial program control system design
Control system design is to live in a gradual, continuous improvement process. In this process, to roughly determine a preliminary control scheme, first of all solve the main control section for less critical monitoring, alarm, display, fault diagnosis and protection measures can not consider.
3. The control requirements determine the input / output element, drawing input / output wiring diagram and a circuit diagram of a main
Select the appropriate input and output according to the PLC input / output control element, calculate the required input / output points and select the appropriate reference to other requirements PLC type. Draw PLC input / output wiring diagram of a control element according to the PLC type and the characteristics of the input / output element determines a correspondence relationship with the PLC input / output terminal of the input / output control. Arranged input / output device should be considered wiring, wiring convenience, the same type of electrical components should row together, it is a good programming ladder. Usually the main circuit is relatively simple, it can be drawn together.
4. The drawing control requirements ladder and the input / output wiring FIG.
This step is key to the whole design process, the design of the ladder need to master the skills and application of PLC programming skills of various instructions, but also understand the basic working principle and structure of the PLC hardware. Ladder correct design is the key to ensuring safe and reliable operation of the control system.
5. Sound design content above
Improve and simplify the ladder drawing, check for missing, then turn if necessary also modify and improve input / output wiring diagram and the main circuit and preliminary design, adding monitoring, alarm, display, fault diagnosis and protection measures Finally, unified sound.
6. Simulation debugging
It is preferably carried out prior to electrical control equipment and wiring mounted on the PLC simulation debugging, emulation or debugging on the simulation software.
7. Equipment installation
The input to the PLC ladder, electric installation and wiring of a control element according to the circuit design, trial runs on the electric control device.