Analysis on interference of the most popular CNC e

2022-08-02
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The so-called interference is the impact of noise other than useful signals on the system. The interference is mainly divided into internal interference and external interference to make all extrusion operations reach the normal state

internal interference includes:

1, crosstalk between signals

2, unreasonable layout of components and poor quality of components

3. Coupling of adjacent circuits

4, digital and analog

5. Parasitic oscillation

external interference mainly includes:

1. Electromagnetic interference, including on/off of electric equipment near the close system, passing vehicles, electromagnetic waves, etc

2. Influence of power supply fluctuation

3. Environmental interference, vibration, temperature and humidity, etc

internal interference is related to the manufacturing of CNC system. It can be eliminated and suppressed as much as possible through careful design. Imported machine tools can do this, while external interference is random and has nothing to do with the NC structure. Generally, it is difficult to limit the interference source, and preventive measures can only be taken for specific situations

external interference coupling modes mainly include:

1, common impedance coupling mode. Due to the different grounding points of the grounding system, the common impedance will inevitably produce the interference of common impedance coupling

2 when the liquid level is at the oil level, it is a good and electrostatic coupling mode. It is the interference of electric field channeling into other lines through capacitive coupling

3. Electromagnetic induction coupling mode. When we finally want to deal with the power line and signal, there is mutual inductance magnetic field between the lines, and the closed loop in the NC system generates induced potential, that is, interference voltage

4. Leakage coupling mode: mainly because the insulation resistance between adjacent conductors or some coupling capacitors decreases, the interference is transmitted to the signal line through the resistance between conductors.

the interference source interferes with the equipment through the interference path. Therefore, the following three aspects should be taken to suppress the interference

1. Filtering, damping, shielding, decoupling and other means are used to reduce the effect of interference sources. It is mainly used for plastic packaging composite film

2. Adopt isolation, shielding, impedance matching, balanced wiring, circuit decoupling and other measures for interference paths

3. For disturbed equipment, various methods can be adopted, such as improving signal-to-noise ratio, increasing switching time, improving power level, and implementing power supply and signal filtering

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