Renishaw's RLS magnetic rotary sensors/encoders
Each sensor of the RLS magnetic rotary sensor/encoders is isolated from the other and can be supplied with a separate power supply. The 2-in-1 units are available with 8-bit to 13-bit sensors. Each sensor can output SSI or incremental position information. Position error between the two sensors is better than ±1 bit. Resolution is up to 8,192 counts/revolution. Speeds are over 30,000 rpm.