What is PLC hardware wiring diagram? Can you give me an example?

The PLC hardware wiring diagram is to draw the connections between the input and output terminals of the PLC and the buttons, switches, indicator lights and other input and output devices in the control system.

It is the same as other control circuit diagrams, except that PLC is one of the devices.

As shown below: PLC is a programmable logic controller, which uses programmable memory to store programs internally, execute user-oriented instructions such as logical operations, sequence control, timing, counting and arithmetic operations, and input through digital or analog

/Output controls various types of machinery or production processes.

Extended information PLC working principle PLC has two basic working modes, namely running (RUN) mode and stop (STOP) mode.

In the running mode, the PLC realizes the control function by repeatedly executing the user program that reflects the control requirements.

In order to make the PLC output respond in time to input signals that may change at any time, the user program is not executed only once, but is repeatedly executed until the PLC shuts down or switches to STOP working mode.

In addition to executing the user program, during each cycle, the PLC also completes internal processing, communication processing and other tasks. A cycle can be divided into 5 stages. This repeated cyclic working method of the PLC is called the scanning working method.

Because computers execute instructions at extremely high speeds, from the perspective of external input-output relationships, the processing appears to be completed simultaneously.

During the internal processing phase, the PLC checks the CPU.

Whether the hardware inside the module is normal, the monitoring timer will be reset and some other internal work will be completed.

In the communication service phase, the PLC communicates with other intelligent devices with microprocessors, responds to commands entered by the programmer, and updates the display content of the programmer.

When the PLC is in STOP mode, only the above operations are performed.

When the PLC is in RUN mode, another three stages of operation must be completed.