The system combines the Tangential-Flow-Technology of the Sartorius AG with established BBI AutomationTechnology. Since 1988, BBI is using DCU (digital controller units) local control units as a standard automation component for fermenters. The current, 3rd generation with touch screen and self explaining user interface, now in addition provides as well a validatable, configurable standard solution for cross-flow systems. Primarily it coversthe implementation of the major process steps, such as concentration, diafiltration, CIP or SIP. With the MFCS/win SCADA system and its flexible, recipe based process control, the DCU process steps can be combined and adapted to individual process requirements.