How to solve the 0-10V signal interference of I/O modules?

To resolve 0-10V voltage signal interference from I/O modules, measures must be taken addressing their high impedance characteristics. At the receiving end, the input impedance is typically high, making it susceptible to noise pickup. Therefore, an RC low-pass filter must be added before the receiver, with a resistor value between 1kΩ and 10kΩ and a capacitor value selected based on the signal bandwidth. Using an operational amplifier to construct a voltage follower for buffering can convert the high input impedance to a low output impedance, enhancing the ability to drive subsequent circuits and resist interference. Shielded cables must be used for signal transmission, with the shield grounded at the receiving end.

On the PCB, the operational amplifier's power supply must be isolated and adequately decoupled using a ferrite bead. For common-mode interference from the power supply, a differential amplifier can be used to receive the signal. If the interference is severe, an isolation amplifier can be used to convert the 0-10V signal from the field side into an isolated voltage or digital signal. In software, digital filtering, such as moving average filtering, can be applied to the ADC sampling results. When troubleshooting interference, an oscilloscope can be used to observe the signal waveform to distinguish between high-frequency glitches, power frequency interference, and random noise, allowing for more targeted filtering or shielding measures.