Definition of professional terms for rotary encoder parameters

When we choose a rotary encoder, there will be some technical terminology parameters. What do these terminology mean? After we take a look, we can more clearly locate the parameters of the rotary encoder we need to be more accurate.

Output pulse number/revolution

The number of pulses output by the rotary encoder for one revolution is usually the same as the number of slots of the grating inside the rotary encoder for optical rotary encoders (the number of output pulses can also be increased to twice the number of slots on the circuit. 4 Times).

Resolution

The resolution indicates the maximum equal fraction of the position data read by the main shaft of the rotary encoder for one revolution. The absolute value type does not output in pulse form, but expresses the current spindle position (angle) in code form. Different from the incremental type, it is equivalent to the "output pulse/revolution" of the incremental type.

Raster

Optical rotary encoder, its grating has two kinds of metal and glass. If it is made of metal, there is a light hole slot; if it is made of glass, a light-shielding film is coated on the surface of the glass, and there is no transparent line (groove) on it. When the number of grooves is small, the metal disc can be grooved by punching or etching. Metal gratings are used in shock-resistant encoders. Compared with metal gratings, they are less resistant to shock. Therefore, please be careful not to apply shock directly to the encoder.

The maximum response frequency is the maximum number of pulses that can be responded to in 1 second (for example: the maximum response frequency is 2KHz, that is, it can respond to 2000 pulses in 1 second)

The formula is as follows:

Maximum response speed (rpm)/60×(number of pulses/revolution)=output frequency Hz

The maximum response speed is the highest speed that can be responded to, and the response formula for pulses generated at this speed is as follows:

Maximum response frequency (Hz)/ (pulse number/revolution)×60=shaft speed rpm

Output waveform Output pulse (signal) waveform.

Output signal phase difference

In the case of two-phase output, the relative time difference between the two output pulse waveforms.

The output voltage

Refers to the voltage of the output pulse. The output voltage will vary due to changes in the output current. Please refer to the output current characteristic diagram for the output voltage of each series

Starting torque

Rotate the encoder shaft at a standstill by the necessary torque. Under normal circumstances, the torque during operation is smaller than the dynamic torque.

Allowable shaft load

Indicates the maximum load that can be added to the shaft, and there are two types of radial and axial loads. For the shaft, the radial load is vertical, and the force is related to the eccentric eccentricity; the axial load is horizontal for the shaft, and the force is related to the force of pushing and pulling the shaft. The magnitude of these two forces affects the mechanical life of the shaft

Shaft moment of inertia

This value represents the inertia of the rotating shaft and the resistance to changes in speed

Rotating speed

The speed indicates the mechanical load limit of the encoder. If this limit is exceeded, it will have a negative impact on the service life of the bearing, and the signal may also be interrupted.

Gray code

Gray code is high-level data, because it is unit distance and cyclic code, it is very safe. Only one change per step. During data processing, Gray code must be converted into binary code.

Working current

Refers to the load current allowed by the channel.

Operating temperature

The data and tolerance mentioned in the parameter table are guaranteed within this temperature range. If it is slightly higher or lower, the encoder will not be damaged. When the working temperature is restored, the technical specifications can be reached

Operating Voltage

The supply voltage of the encoder.