A rotary encoder is a photoelectric rotary measuring device that directly converts the measured angular displacement into a digital signal (high-speed pulse signal).
The encoder is divided by signal principle, and there are incremental encoders and absolute encoders.
We usually use an incremental encoder, which can directly input the output pulse signal of the rotary encoder to the PLC, and use the high-speed counter of the PLC to count the pulse signal to obtain the measurement result. Different types of rotary encoders have different phase numbers of output pulses. Some rotary encoders output A, B, and Z three-phase pulses, and some have only two phases, A and B. The simplest is phase A.
The encoder has 5 leads, 3 of which are pulse output lines, 1 is a COM end line, and 1 is a power line (OC gate output type). The power supply of the encoder can be an external power supply, or it can directly use the DC24V power supply of the PLC. The "-" end of the power supply should be connected to the COM end of the encoder, and the "+" should be connected to the power supply end of the encoder. The COM end of the encoder is connected to the COM input terminal of the PLC. The A, B and Z two-phase pulse output lines are directly connected to the input end of the PLC. A and B are pulses with a difference of 90 degrees, and the Z-phase signal is rotated only once in the encoder. A pulse, usually used to make the basis of the zero point, pay attention to the response time of the PLC input when connecting. The rotary encoder also has a shielded wire. When used, the shielded wire should be grounded to improve the anti-interference.
Encoder manufacturers produce a full range of products, generally dedicated, such as elevator-specific encoders, machine-specific encoders, servo-motor-specific encoders, etc., and the encoders are intelligent, with a variety of parallel The interface can communicate with other devices.
An encoder is a device that converts an angular displacement or a linear displacement into an electrical signal. The former becomes the code wheel and the latter is called the code ruler. According to the readout mode, the encoder can be divided into contact type and non-contact type. The contact type uses a brush output, and a brush contacts the conductive area or the insulating area to indicate whether the state of the code is "1" or "0"; the non-contact receiving sensitive element is a photosensitive element or a magnetic sensitive element, and when the photosensitive element is used The light transmissive area and the opaque area indicate whether the state of the code is "1" or "0".