Nowadays, more and more machine tools are controlled by plc. The control of PLC can simplify the circuit and make the design simpler, safer and more reliable. Some advanced PLCs have a variety of interfaces to achieve connectivity, Internet access and other functions. Allows people to remotely control the device. So, how can we design a machine controlled by PLC? In my experience, at least understand the following aspects: Passive Stylus Pen,Custom Stylus Pen,Stylus Pen For Surface,Smart Stylus Pen Shenzhen Ruidian Technology CO., Ltd , https://www.wisonen.com
1 Know the working principle of PLC The programmable controller is also called PLC. It is similar to the relay system. The PLC is also composed of the input part, the logic part and the output part. The input part collects and saves the data actually run by the controlled part, and the logic part processes the input. Part of the information obtained and to determine which functions need to respond to the output. The output section provides a number of devices that are being controlled, and which devices require real-time operational processing. The PLC uses a microprocessor and a memory composed of large-scale integrated circuits to form a logical part. Although the logic part is similar to the relay control system, its composition, working principle and operation mode are completely different from the former. Through programming, you can flexibly change its control program, which is equivalent to changing the hard wiring of the relay. This is called "programmable".
2 After mastering the PLC language and instructions, knowing the working principle of the PLC, it is easier to understand its language. The most common PLC language is ladder diagram and statement table. The ladder diagram is the most intuitive and easy to use. To learn more about the relevant textbooks, it should be emphasized that although the principle is the same, the basic instructions are similar, but the different PLC instruction symbols of the manufacturer will be different. For example, the same as the rising edge differential, Mitsubishi products are represented by PLS, Omron The company is called DIFU, and Siemens is │P│. These specific differences depend on the programming manual for various products.
3 Learn to use a variety of programming software. After programming a program, you need to input it into the PLC. In the past, more handheld programmers were used. Manual input is more troublesome and error-prone. In recent years, with the popularity of computers, it has gradually been replaced by various programming software. For example, Yonghong's WinProladder editing software, ohm company's CX-PROGRAMMER. Siemens STEP-7-MICRO-WIN32 and so on. These tools can be run in the WINDOWS environment. It is very convenient to use. When you select a manufacturer PLC, you must learn to use its programming software, because it will greatly save your programming and debugging time. Take Yonghong's WinProladder editing software as an example. When programming, it can provide you with the input range of operands and quickly search for special instructions. According to the ladder diagram, the statement table is automatically generated, and the syntax error is pointed out. When debugging, it can quickly and accurately transfer the program to the PLC through the data line, and then monitor the execution state, and the input/output points can be forcibly set/reset. Online editing is also possible. In short, when you are proficient in the use of programming software. It will definitely be able to complete the design task with less effort.
4 understand that PLC control signals have those
The PLC controls the output signal according to the input conditions. The input signal is the button on the console, the limit switch on the machine, the pressure relay and the photoelectric switch, and the output point controls the on/off of the relay or the contactor coil, the indicator light is extinguished, and the hydraulic valve electromagnet is Pull in and output the signal terminals of the inverter. When we do a machine design, we often encounter two problems. One is that the number of expandable I/O points of the PLC is limited, and the other is to increase the number of I/O points to increase the cost. So we need to know which signals are controlled, how many are each, count how many input and output points are needed, and select the PLC accordingly.