The programmable controller is known for its strong volume function. It can not only easily complete the functions of order logic, exercise control, timing control, counting control, digital operations, data processing and other functions, but also can be established and output interfaces. The connection between the number of mechanical numbers and the simulation quantity achieves automatic control of the production process. Especially now, due to the advent of Electric Filter Fan Cabinet Heater Fan Heater with Thermostat the information and network age, the PLC function has been extended, which makes it have a strong network of communication capabilities, which is widely used in many industries.
1. Sequential control
Sequential control is the most basic and most widely used field of PLC. The so -called sequential control is in accordance with the order of the process process, under the action of the control signal, the various executive agencies of the production process automatically activate in order. Because it also has the advantages of flexible programming design, fast speed, high reliability, low cost, and easy maintenance, it can completely replace the traditional relay contact control system in the realization of single -machine control, multi -machine group control, and production process control. It is mainly based on the operation of the instructions and sensor signals given by the operation according to the operation of the operation according to the operation of the operation. Compared with the control of automatic elevators, the automatic turnover and closing of electromagnetic section on the pipeline, the order of the belt transport aircraft, etc. For example, the raw material mixing system of the sub -factory uses the order control function of the PLC.
2. Control of closed -loop process
In the past, the simulation amount of process control used a PID simulation regulator composed of hardware circuits to achieve opening and closed -loop control. Now you can use the PLC control system to choose an analog control module. The function is completed by the software. , Can control multiple control circuits and multiple control parameters at the same time. For example, temperature, flow, pressure, speed, etc. during production.
3. Movement position control
PLC can support the control and management of CNC machine tools. In the mechanical processing industry, the programmable controller and computer CNC (CNC) are integrated to complete the movement position control of the machine tool. Its function is to receive processing information of input device input. After processing and calculation, the corresponding pulse is issued to the driver device. By stepping on the motor or servo motor, the machine tool moves according to the scheduled rail movement to complete the self -control of the multi -axis serviced motor. At present, it is used in applications such as unintentional grinding, stamping, complicated parts of parts of parts, and scrolls.
4. Monitoring and management of the production process
PLC can be connected to peripherals such as the display terminal and printer through the Tongxun interface. The display as the human -machine interface (HMI) is an intelligent device containing a micro -processing chip. It is combined with the PLC to replace the many control buttons on the electro -control cabinet, select switch, signal indicator lights, and production process simulation screens and electricity A large number of intermediate relays and terminals in the control cabinet. All operations can be performed on the operation element on the display. The PLC can easily and quickly collect and process the data in the production process, and can be displayed on the parameters to be displayed in the methods of binary, decimal, hexadecimal, ASCII character. On the display screen, the running status of the on -site device through the color change of the icon, such as the opening and passing of the valve, the start and stopping of the motor, the status of the location switch, etc. Comprehensive methods such as data and rod maps such as PID circuit control reflect the amount of changes in the production process. The operator can adjust the parameter through the parameter settings. It is convenient for future production management and analysis of process parameters.
5. Network characteristics
PLC can realize the communication requirements between multiple PLCs or multiple PLCs and a computer, thereby forming a multi -level distributed control system to constitute a factory automated network.
(1) Monitoring of the control system through communication modules, upper machines, and corresponding software.
2) Connect with the remote client computer by the modem and the public telephone network, so that the manager can perform long -distance monitoring of the control system through the telephone line.