Do you know how the S7-200 controls the speedometer?

Analog: 0-5V, 0-10V, 4-20mA

This post was last edited by kevin19821221 on 2018-7-18 10:22. Is the motor AC or DC? In the case of an AC motor, the PLC controls the frequency converter to adjust the speed, with current or voltage analog signals being sent to the frequency converter to change its frequency. If the speed changes with the load, an encoder is installed on the motor to provide real-time feedback to the PLC. The PLC then uses PID control to adjust the frequency of the inverter, thereby keeping the motor speed constant. For high-power DC systems, the PLC controls the DC speed regulator; the type of signal output depends on the interface type of the DC speed regulator. If it is a stepper motor, the PLC controls the stepper driver, using PWM for speed control. If it is a servo motor, the PLC controls the server, using PWM for speed control. PTO is used to control the motor’s position; it is not possible to adjust the speed, as PTO maintains a fixed pulse width (duty cycle). The speed is related to the pulse width, and only by adjusting the pulse width can the speed be changed.

It was only after replying that I realized the original poster was referring to a PLC-connected speedometer; I’m not quite sure what they meant by a control speedometer – does a speedometer have an actuator? If one wants to use a PLC to change the value displayed on a speedometer, it is first necessary to determine the type of signal input used by the speedometer. Generally, speedometers detect pulse signals; the user needs to figure out the relationship between speed and the number of pulses, and then use the PLC’s pulse output to send these signals to the speedometer in order to change its display value.