Scales in RK7
1.1. Scales are used for menu item weight definition.
1.2. You may use scales to weight non by weight sellable menu items like drinks in bottles in the course of inventory (see https://docs.rkeeper.ru/rk7/7.6.5/ru/english-manuals/scales-in-rk7).
2.1. Add port (COM usually) and scales drivers to cash station.