Encoder Interface

The Ultra5000 main encoder feedback connector is CN2. The motor encoder

interface circuitry features include:

• 2.5 MHz maximum line frequency

• RS-485 serial channel for communicating with intelligent encoders

• Hall input for start-up commutation only

• Interpolation of sine/cosine encoders

All encoder signals are filtered using analog and digital filtering. The inputs

also include illegal state change detection. Refer to Figure 2.5 for a schematic

of the motor encoder inputs.

Hardware latches can be used for latching the encoder position based on an

index input or a digital input transition.

Auxiliary Encoder Interface

All encoder input signals (CN1B) are filtered using analog and digital filtering,

including illegal state change detection.

The input circuitry includes pull-up and pull-down resistors for compatibility

with single-ended and open collector signals, in addition to differential signals.

A single channel schematic of the auxiliary encoder interface is shown in the

figure below.