（1） Firstly, the PLC system has its own dedicated grounding, which can easily solve many interference problems.

（2） PLC power supply with isolation transformer can eliminate interference sources from the power input side

（3） Adding a 1:1 signal isolator can directly eliminate interference sources from the signal source side.

（4） Adding magnetic rings can eliminate interference sources in signal transmission lines.

（5） Switching signals and analog signals should be separated, and analog signals and digital signals should not share the same multi-core cable, let alone power lines. From the perspective of comprehensive wiring, they should be separated from interference sources as much as possible.

（6） It is best to use separate shielded wires for analog signals, suspended on the input and output sides, and grounded on the PLC side to directly protect the signal source.

（7） The best signal type is 4-20mA, and the signal source should be strengthened.

（8） The analog signal load is of the solenoid valve type, so it is best to choose a 1.5 wire to reduce the attenuation of the signal source.

（9） Signal cables should be kept away from strong interference sources such as frequency converters, high-power silicon rectifiers, and large power equipment, and the signal source should be kept away from strong magnetic field interference sources as much as possible.

（10） In software, algorithms such as digital filtering or ramp functions are used to filter interference signals. There is no other way, and software can compensate for hardware defects.