The MQR350A is a “quasi-absolute” encoder.
"Quasi-absolute" means that it is an incremental encoder that provides a valid absolute position only after initialization.
Therefore the belt lock must pass the sensor head twice in the same direction. The zero position will then be set to the middle of the belt lock and the encoder delivers valid absolute position data.
MQR350A - HDmag flex
Mating connector M23, solder version, 17-pin, CCW
Mating connector M23 in solder version (17-pin, female , CCW) for cable connection to the flange connector M23 (17-pin, male , CW).