The ACNET Data Consolidator

B. Lublinsky
Fermilab


Many of Fermilab's control systems are located around the Ring and are doing measurements for the specific houses. Examples of such systems are: Cryogenic controls, BPMs, QPMs, Vacuum, etc. Very often users are interested in the similar data collected around the ring that allow them to understand the global characteristics of the process. There are 2 ways of accessing these kinds of data: individual reads from different houses or "ring-wide" reads. Obviously, from the user point of view and from the point of view of resource utilization "ring-wide" reads are much more convenient. Up until recently all control modules were connected to CAMAC links and served by the same Front End computer that was implementing "ring-wide" consolidation. During the last several years the situation has changed significantly, the new generation control systems are connected directly to the network; thus it was necessary to introduce a network server to consolidate messages to remote control systems.

The network consolidator is VxWorks based 68040 microprocessor, residing in a VME chassis, that can communicate on both Ethernet and Token Ring (the two networks used in the Fermilab control system). Consolidator software is table driven consolidation - user specifies the consolidation table that he wants to use and his request is resent to all nodes that are in the table. The reply from all nodes is assembled together and sent back to the original requester. Internally, consolidator is based on the dynamic pool, that is keeping track of all currently active requests and making sure that requests to the remote nodes are not duplicated. It also combines internal requests to the remote nodes, thus minimizing the network traffic. Currently consolidator is used to perform "ring-wide" requests for the cryogenic control system. There are plans to use it for BPM "ring-wide" support.