CANDIDE - a Fieldbus System to Control Front-end Electronics

W.Heubers, R.Hart, H.Boterenbrood, I.Weverling, P.Rewiersma
National Institute for Nuclear and High-Energy Physics Amsterdam


The CANDIDE system is initially developed to control and monitor functions and variables present in the front-end electronics of a prototype of a subdetector for the ATLAS * inner tracker. CANDIDE is based on the Controller Area Network (the CAN fieldbus), as it is defined by Bosch from Germany for the automobile industry. Low cost, reliability and real-time capabilities were important issues to select this fieldbus for the control of the front-end electronics. Prototype CAN nodes, based on the Philips 80C592 micro-controller, are built to control functions such as setting discriminator thresholds, masking noisy channels and monitoring temperature sensors of the channels in the ATLAS subdetector. This paper describes in more detail the implementation of a network of these prototype CAN nodes and the protocol to exchange messages between the nodes and a PC or Unix host. In addition to this some remarks will be made about the work just started to design a virtual fieldbus controller for the Cortex control system as it is developed by the CICERO group from CERN.

*ATLAS, a planned HEP detector for the LHC facility at CERN.