In industrial automation control systems, the access of analog signals is an important part of achieving accurate control. Connecting an analog signal to a PLC is a critical step in achieving this goal. This article will detail the four steps of connecting an analog signal to a PLC.
Sensors play a crucial role in industrial production processes. They are able to detect changes in the object being measured and convert these changes into inductive signals. These inductive signals can be electrical, optical, or thermal, depending on the type of sensor and the nature of the object being measured. When the sensor detects changes in the measured object, it immediately converts these changes into corresponding electrical signals and outputs them.
The inductive signal output by the sensor is usually non-standard and cannot be directly received by the PLC. Therefore, a transmitter is required to convert these signals into standard voltage and current signals. The function of the transmitter is to linearize the non-standard inductive signal and convert it into a standard 4-20mA or 0-10VDC voltage and current signal. In this way, the PLC can receive these standard signals through the input module for subsequent processing and calculation.
In the process of connecting analog signals to PLCs, AD conversion modules play a vital role. It further converts the standard voltage and current signals output from the transmitter into digital signals. A digital signal is a type of signal that a PLC is capable of processing, and it is capable of converting continuously varying analog quantities into discrete digital information. Through the APP conversion module, the PLC can accurately obtain the real-time status and change of the measured object.
Finally, the CPU will further process, calculate and sort out the digital signals converted by the APP conversion module. The CPU is the brain of the PLC, which can perform logical operations, arithmetic operations, data processing and other operations on the input digital signals, and output the operation results to the output module. Through this step, the PLC can accurately control the control object according to the real-time status and change of the measured object, and realize the optimization and adjustment of the automated production process.
In short, the process of connecting the analog signal to the PLC needs to go through four steps: sensor detection, transmitter conversion, APP conversion module conversion, and CPU processing calculation. These steps work together to achieve accurate access and processing of analog signals in industrial automation control systems. In this way, we are able to better grasp the status and changes of the measured object, and improve the level of automation and control accuracy of the production process.