The DAQ system for CLEO III

Abstract In 1998 the CLEO detector collecting data at the CESR storage ring will be upgraded. A new Data Acquisition system will be installed during the upgrade to record triggers up to 1000 Hz with a mean data size of 25 KBytes per event. In this largely improved system, we will exploit the new CBLT VME transfer mode (defined by VIPA) to readout crates with about 15 9U digitization cards. Secondly, we decided to design and build a FASTBUS-VME interface card with the dimension of a FASTBUS card, and a 2-slot VME backplane inside. With this interface, all hardware and software will be homogeneous at this point of the DAQ data pipeline. It will also perform additional sparsification and channel tagging “on the fly”. This new system will be monitored and controlled by a networked system of CPUs. To achieve a dynamical and simple connection method between the various processes we chose the CORBA standard communication method. The port to PowerPC based VME boards was done in close collaboration with Visigenic Corp.