CIRCUS is a compact integrated robot controller unit and servo amplifier for further 7 degrees-of-freedom internal robot arms on the ISS and the attached grippers. Such an arm would be used for, e.g., repetitive payload handling.
CIRCUS was confirmed in a modular way which allows easy in-orbit replacement of subsystems (ORUs). It may accept commands from the OB DMS (on-board data management system) or from the Crew PC and to report status data to the OB DMS and the Crew PC.
We developed different hard- and software modules for CIRCUS, e.g., the power supply unit with six independent, galvanically separated voltages operating from 28V dc at a level of 220W, and the interface from the SERCOS communication bus to the ISA PC-bus. In addition a set of driver and test routines were developed during this activity.