Controller Area Network (CAN) - A Fieldbus Gives Access
to the Bulk of BESSY II Devices

B. Kuner, R. Lange, I. Muller, G. Pfeiffer, J. Rahn, H. Rudiger, BESSY


The superior properties of the CAN fieldbus will be widely utilized for BESSY II. Literally any power converter, the PLC of the radio frequency, vacuum valves and gauges etc. will be interfaced by embedded controllers attached to a CAN segment. Further more it is envisaged to set up a feed forward insertion device compensation scheme that is based on a specific CAN installation. Today a unified data exchange convention (called SCI: Simple CAN Interface) facilitates development of communication tasks between CAN chips of different manufacturers on the embedded controllers or the VME master. The usefulness of the specific subset CAN Message Specification (CMS) of the CAN Application Layer (CAL: proposed standard) protocol is under study.