Emerson CE4022 Controller, Shanghai Sijian Intelligent Technology Co., Ltd. is engaged in technical development, technical consultation, technical transfer in the fields of intelligent technology, information technology, and automation technology, as well as the sales of electrical equipment, automation equipment, electronic products, communication products, and electromechanical products. Industrial automation products include: PLC, DCS, sensors, frequency converters, encoders, relays, servo drives, soft starters, and touch screens. The brands involved in the products are: Eurotherm, Schneider, Siemens, ABB, SICK, P+F, E+H, Yokogawa, Yamakawa, Mitsubishi, Emerson, Honeywell, FANUC, GE, Eaton Electrical, CT,

Emerson CE4022 Controller, The user's requirement for closed-loop control of the frequency converter on-site is: the frequency converter can automatically adjust the speed of the variable frequency pump based on changes in the user's system water consumption, achieving constant pressure water supply in the pipeline network; at the same time, the target pressure value can be set on the LCD screen.

The detailed programming process is as follows: The PLC reads the instruction (FROM) to obtain the user's water pressure feedback value, stores the feedback value into the D12 data address of the PID instruction using the move instruction (MOV); stores the user's water pressure set value into the D10 data address of the PID instruction using the move instruction (MOV); D200～D222 store the working parameters of the PID; D14 is the output value of the PID instruction operation, which is written to the analog output module via the PLC's write instruction (TO), and then converted by the analog output module into an analog signal of -10V～10V or 4～20mA, which is sent to the high-voltage frequency converter controller for frequency setting.

When setting the PID working parameters, the P, I, and D parameter settings are particularly important, as their quality directly affects the water pressure control of the pipeline network. P represents the proportional gain, with a setting range of 0～99(%). A larger proportional adjustment setting can speed up the adjustment and reduce errors when the system exhibits deviations, but an excessively large proportional gain can cause system instability; I represents the integral time, with a setting range of 0～32767(*100ms). The smaller the integral time, the stronger the integral effect, and conversely, the larger I is, the weaker the integral effect; D represents the derivative time, with a setting range of 0～32767(*10ms). Derivative adjustment has an advanced control effect, and an appropriate derivative time can improve the dynamic performance of the system.