SIN/COS Encoder
A Sin/Cos encoder is a position feedback device similar to a quadrature encoder, except instead of outputting digital pulses, it outputs analog voltages with sinusoidal shapes offset by 90°. Provides absolute positions from the start, but its sensitive to EMI and requires special filtering, transient protections and shielded wiring.
from the description of vesc what's the meaning of EMI?
electromagnetic interference: https://www.techtarget.com/searchmobilecomputing/definition/electromagne...(EMI)%20is%20unwanted,malfunction%20or%20stop%20working%20completely.
It affects both digital and especially analog signals. The longer your wires and the stronger the source of the interference is, the more signal corruption you should expect. And the three phases swinging at high current are great sources of such inferences. Pretty much all analog inputs in the controller such as throttles and regen having wires of more than a foot needs good filtering (low pass filter usually works fine), or expect unpredictable behavior. Shielding and strategic placing of connectors to minimize the length of the wires need to be considered.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
EMI its next to EMP but in micro scales