DESIGN OF A REMOTE DATA SUBSCRIPTION MECHANISM

The CERN 26Gev Proton Synchrotron (PS) accelerator complex produces a sequence of different beams in cycles of a duration of 1.2 sec or mult iple of it. A Main Control Room operator, supervising the functioning of (part of) an accelerator for a particular beam, needs to coherently display on his workstation the beam-dependent data, in 'synchronism' with this particular cycle (within a certain time delay). The classica l data collection via synchronous Remote Procedure Calls cannot fully answer to these requirements. The PS Data Subscription Mechanism addre sses the above-mentioned problems: it allows a client application in a Workstation to dynamically request accelerator data synchronised to a particular beam; the client collects data related to the same beam fr om different front-ends The paper exposes the CERN PS specific require ments, and the solution proposed, based on functional data-groups and providing the additional functionality of monitoring process data (i.e ., send on change).