How to repair the common wiring method and fault of the encoder

How to repair the common wiring method and fault of the encoder?

An encoder is a device that compiles and converts a signal (such as a bit stream) or data into a signal form that can be used for communication, transmission and storage. We usually use incremental encoders, which can directly input the output pulse signal of the rotary encoder into the PLC, and use the high-speed counter of the PLC to count the pulse signal to obtain the measurement result. The number of phases of output pulses varies by model. There are rotary encoders that output a, b, and z three-phase pulses, and there are also rotary encoders that only output two-phase a, b-phase pulses. The simplest is only phase a. The encoder has 5 wires, 3 of which are pulse output wires, 1 is a COM terminal wire, and 1 is a power wire (OC grid output type). The power supply of the encoder can be an external power supply, or directly use the DC24V power supply of the PLC. The "-" side of the power supply is connected to the COM side of the encoder, and the "+" side is connected to the power side of the encoder. The COM terminal of the encoder is connected to the PLC input COM terminal, and the A, B, and z two-phase pulse output lines are directly connected to the input terminal of the PLC. A and B are pulses with a difference of 90 degrees. The Z-phase signal is when the encoder rotates 1 circle. There is only one pulse, which is usually the basis for the zero point. Therefore, the PLL rotary encoder also has a shielded wire, so please ground the shielded wire to improve anti-interference.

How to repair the common wiring method and fault of the encoder?

(1) The fault of the encoder itself: it means that the parts of the encoder itself are faulty, and the correct waveform cannot be generated and output. In this case, you need to replace the encoder and maintain its internal equipment.

(2) Encoder +5V power supply drops: +5V power supply is too low, usually not below 4.75V. The reason for the too low is the failure of the power supply and the increase of the resistance of the power transmission cable, which causes losses. In this case, you need to check the power supply and replace the cable.

(3) Loose encoder installation: This kind of failure will affect the accuracy of position control, and the position deviation during stop and movement will temporarily deteriorate. After the power is turned on, an overload alarm of the servo system will occur. Please pay special attention.

(4) Absolute encoder battery voltage drops: This fault is usually a meaningful and clear alarm. In this case, the battery needs to be replaced. When the position memory of the reference point is lost, it is also necessary to perform the operation of returning to the reference point.

(5) Encoder connecting cable failure: This type of failure has the highest probability of occurrence. It is often encountered in maintenance and should be a priority factor. Usually, the encoder cable needs to be replaced due to broken wire, short circuit or poor contact. In addition, since the cable is not firmly fixed, welding and disconnection caused by looseness, special attention should be paid to whether the cable needs to be tightened.

(6) The shielding wire of the encoder cable is not connected or falling off: it is necessary to introduce interference signals, the waveform is unstable, which affects the correctness of communication, and the reliable welding and grounding of the shielding wire are ensured.

(7)The grating pollution will reduce the signal output amplitude, so it is necessary to dip anhydrous alcohol on the absorbent cotton and gently wipe off the oil.

The above is about: How to repair the commonly used wiring method and fault of the encoder? If you have any questions about encoders, please visit the official website of okplazas.com: www.okplazas.com for consultation. It is a production enterprise specializing in R&D, production, sales and coupling processing of industrial encoders.