Detection of load cells associated with weight changes at a fixture

Items may be stored on a fixture of a facility using one or more accessories, such as trays or bins. Weighing modules that include one or more load cells may be mounted to a crossbar of the fixture. The accessories of the fixture may then be mounted to the crossbar via the weighing modules. The load cells within each weighing module can collect weight data associated with items stowed in the accessories that are coupled to the weighing module. When a weight change is detected at the fixture, a particular load cell is identified as the source of the weight change. Once a load cell is identified, the accessory coupled to the load cell is identified, as well as the types of items stowed therein. Interaction data can then be determined to indicate a type of item that was added to or removed from the accessory of the fixture.