Modular switching device for temporarily storing workpiece carriers of linear transportation system

The invention relates to a modular transfer device for temporarily storing workpiece carriers of a linear transport system, to an operating method for a modular transfer device (1), to a control unit (30) and to a machine-readable program code (31), which transfer device can be arranged on workpiece carriers (WT1, WT2, WT3, WT4, WT5, WT6) transported on a transport surface (N). The invention relates to a transfer device (1) between a transfer region (W), in particular a placement and/or extraction region, and a processing region (B) of a linear transport system (WT1, WT2), comprising a horizontally arranged first (2) and second (3) carrier units, which are arranged vertically one above the other and are fixedly spaced apart from one another, on which carrier units guide devices (4, 5) are arranged, when interacting with the conveyor belt (21), the workpiece carriers can be transported in the transport direction (T) by means of the guide device, and the support units can be adjusted together in the vertical di