It is the switching station between the PC and the individual components of the viscosity measuring system and, using one of the three selectable modules, coordinates the tasks and operations of all other parts of the system. The unit can be fitted with up to 4 modules:The 1-place module (only on the PVS 1/1) provides a low-cost single-place measuring system with the option of adding measuring places at any time. This module can operate a single test stand S5 and can also coordinate the operation of a VRM 1 or a VRM 2 rinsing module with the stand, if required.