S/C – Sin/cos encoder

The sin/cos encoder (S/C) block retrieves the Sine and Cosine signals of a sin/cos encoder connected to the Motor Interface.

The B-Box RCP supports up to two sin/cos encoders through the Motor Interface for B-Box RCP. This type of sensor encodes the position of the rotor using two signals in quadrature (sin and cos). The principle is similar to an incremental encoder: the signals in quadrature are periodic, and the sensor produces a fixed number of periods per revolution (PPR). Unlike an incremental encoder, signals in quadrature are analog, which allows computing the angle within one electrical period of the sensor. As a result, a sin/cos encoder offers a better resolution at the same PPR. Additionally, some sin/cos encoders also provide an index signal (ns) equivalent to the Z reset signal of an incremental encoder. The Motor Interface does not support absolute sin/cos encoders.

Version 3.7 beta of the ACG SDK for Simulink does not implement an angle decoder. Instead, the S/C block provides the raw analog signals of the sensor read by some ADCs, and the control must implement angle decoding.

Simulink block

Signal specification

• The output s/c is a vector containing the Sine and Cosine signals in [V].
• The optional output ns corresponds to the index signal.
• The sim input is used in simulation and represents the actual Sine and Cosine signals, computed by the simulation plant model.
• The > input signal needs to be connected to the sampling clock generated by the CONFIG block to account for the exact sampling instant in simulation.

Parameters

• Device ID selects which B-Box/B-Board to address when used in a multi-device configuration.
• Motor Interface input selects which connector of the Motor Interface is used as an input.
• Output index signal defines if the index signal is output or not.

PLECS block

Signal specification

• The output s/c is a vector containing the Sine and Cosine signals in [V].
• The optional output ns corresponds to the index signal.
• The sim input is used in simulation and represents the actual Sine and Cosine signals, computed by the simulation plant model.
• The > input signal needs to be connected to the sampling clock generated by the CONFIG block to account for the exact sampling instant in simulation.

Parameters

• Device ID selects which B-Box/B-Board to address when used in a multi-device configuration.
• Motor Interface input selects which connector of the Motor Interface is used as an input.
• Output index signal defines if the index signal is output or not.

C++ functions

void MotInt_EnableMotorInterface(unsigned int device=0);Code language: C++ (cpp)

float Sc_GetSin(tMotIntMachine machine, unsigned int device=0);Code language: C++ (cpp)

float Sc_GetCos(tMotIntMachine machine, unsigned int device=0);Code language: C++ (cpp)

float Sc_GetNs(tMotIntMachine machine, unsigned int device=0);Code language: C++ (cpp)