General steps for designing the hottest PLC contro

General steps of PLC control system design

when designing the PLC application system, the first step is to design the function of the PLC application system, that is, according to the function and process requirements of the controlled object, clarify the work that the system must do and the necessary conditions. Then, the function analysis of the PLC application system is carried out, that is, through the analysis, in order to help the function of the made in China 2025 system, the structural form of the PLC control system, the type and quantity of control signals, and further expand the scope of its TPE, the scale and layout of the system. Finally, according to the results of system analysis, the specific type of PLC and the specific configuration of the system are determined

plc control system can be designed according to the following steps

1. be familiar with the controlled object, formulate the control scheme, analyze the process and working characteristics of the controlled object, understand the cooperation between the machine, electricity and liquid of the controlled object, and determine the control requirements of the controlled object for the PLC control system

2. determine the I/O equipment. According to the control requirements of the system, determine the input (such as buttons, travel switches, selector switches, etc.) and output equipment (such as contactors, solenoid valves, you need to check these two key points, signal indicators, etc.) required by the user, so as to determine the I/O points of PLC

3. the selection of PLC mainly includes the selection of PLC model, capacity, I/O module and power supply

4. Assign the I/O address of PLC, and determine the model, specification and quantity of control buttons, selection switches, contactors, solenoid valves, signal indicators and other input and output devices according to the on-site needs of production equipment; List the comparison table of input/output equipment and PLC input/output terminals according to the selected PLC model, so as to draw the PLC external I/O wiring diagram and compile the program

5. Design software and hardware, PLC program design, control cabinet (table) and other hardware design and site construction. Because the program and hardware design can be carried out at the same time, the design cycle of PLC control system can be greatly shortened. For relay system, all electrical control circuits must be designed before construction design

6. online debugging online debugging refers to the unified debugging of the program that has passed the simulation debugging. At the beginning, do not take the output equipment (contactor coil, signal indicator and other loads) for debugging. Using the monitoring function of the programmer, the method of subsection debugging is adopted. After all parts are debugged normally, the actual load can be put into operation. If it does not meet the requirements, adjust the hardware and program. Usually, only some programs need to be modified, and after all debugging is completed, it can be delivered for trial operation. After a period of operation, if it works normally and the program does not need to be modified, the program should be solidified into EPROM to prevent the program from being lost

7. Sort out technical documents, including design instructions, electrical installation drawings, list of electrical components, operation instructions, etc. (end)