Requirements for the receiving interface
The receiving interface must be able to process the signals, which are provided via open collector circuits (fig. 1). Output signal features are listed in table 1. The phase shift is the delay between the two signals’ rise events (fig. 2). It is 1/4 of the period, or 90 electric degrees. The duty cycle value is the high state of the signal compared to the full period (fig. 2). It is nominally 50%.
Power supplySKF motor encoder units require a regulated voltage supply, which can range from 5 to 18 V DC. For applications above 18 volts, contact SKF.
ResistorsPull-up resistors (table 2) should be placed between the voltage supply and the conductors for the output signals to limit the output current to 20 mA. The application load resistance between the ground line and the conductors for the output signals should be at least 10 times higher than the resistance of the pull-up resistor. This helps to keep the output signals readable.
Detecting direction of rotationA positive phase shift corresponds to signal B rising before signal A and indicates the inner ring rotating clockwise when viewed from the sensor side.
SKF motor encoder units can be used in systems operating in very arduous electromagnetic environments as described in the international standard IEC 61000-6-2.
All standard SKF motor encoder units are protected with high-performance filtering so that they can adapt to the electric environment typically found in industrial and automotive applications.
- Motor encoder units with a free cable end have the filter included in the overmoulding on the cable.
- Units with an AMP Superseal™ connector have the filter integrated in the connector.