Eltomatic offers two solutions for mounting/retrofitting a shaft encoder into a mechanical register.
Without printer:
If the mechanical register is not fitted with a printer, Eltomatic offers solutions using both the shaft encoders type 01-08 and type 01-09. The encoder is mounted onto a mounting bracket and placed in the mechanical register where the printer part normally sits.
With printer:
If the mechanical register is fitted with a printer, Eltomatic offers a solution using the shaft encoder type 01-09, which can be mounted on the bottom of the mechanical register's printer part. In this cases, the shaft encoder should be CCW adjusted.