User Manual

Table Of Contents

Sinusoidal Commutation

Advanced Digital Motor Controller User Manual 111

output from the sensor and captured by the controller. Rotate the motor by hand to verify

that the counter changes.

The 12 to 15 bit raw value of the SSI sensor can be read using the query:

?CSS [channel]

The continuous 32-bit counter and speed that is driven by the SSI sensor can be read us-

ing the following queries respectively:

?CSS [channel]

?SS [channel]

Typically, SPI encoders are single pole sensors, meaning that they output 0 to their maxi-

mum value over a full mechanical turn.

Important Notice

The SSI sensor is used for commutation only. It cannot be used for position mode.

Use single turn sensor only. Multi-turn sensors are not supported.

Preparation for Automatic Sensor Setup

The rotor’s angle sensor is a critical element for good sinusoidal commutation. Wrong or

unstable angle reading can cause excessive current consumption, vibration, or even dam-

age. The sensor must be correctly and ﬁrmly attached to the motor so that it never slips

during operation. The table below shows the setup and calibration steps required for each

sensor type.

Setup Encoder Hall

Hall+

Encoder SSI

Sin/

Cos Resolver

Min/Max Range Calibration No No No No Ye s Ye s

Zero reference search Yes(1) No No Ye s Ye s Ye s

Hall Position Mapping No Yes(2) Yes(2) No No No

Linearity Correction Map No(3) No No(3) Yes(3) Ye s Ye s

Sensor/Winding Order Ye s Ye s Ye s Ye s Ye s Ye s

Note 1: Zero reference search must be performed at every power-up for Encoder mode

Note 2: Hall position mapping is optional but recommended for best results

Note 3: Linearity Correction is optional for digital encoders

Sensor setup and calibration is generally a one-time procedure. Sensor information is

stored in the controller’s conﬁguration and calibration ﬂash.