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| Each one of the 4 DEVILs has a circular buffer of 1927 lines named "sockets". Write operations of the four circular buffers are synchronized via a common stobe strobe so that the four write pointers are always alligned. At each strobe, each DEVIL stores a "socket" composed as:
DBL ACQNum [0, 1926]; The socket header is written twice: at the beginning of the socket (before part X) and again in the middle of the socket (before part Y) the content of the two headers being the same; this is due to historical reasons and – although it is a waste of memory space – it was left in order not to compromise the functioning of other pieces of code that access the same memory area.
[DBL] 32 values of the BPM X signals from the Bergoz modules read from that DEVIL;
[DBL] 32 values of the BPM Y signals from the Bergoz modules read from that DEVIL. The 32 components in part X and Y are ordered according to the cabling and do not necessarily follow the sequence of the BPMs along the vacuum chamber. Moreover the 32 values refer to both e- and e+ rings for which the BPMs sequence is obviously different. As a consequence, part X and Y must be considered as raw containers and their content must be further processed in order to reconstruct the real orbit. |
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This VI is a functional global that stores, holds and returns the last X and Y parts acquired from the 4 DEVILs (as they come out from the readDEVILSocket VI). The X and Y arrays have 32 components, such as the number of channels of the multiplexer connected to the DVM. This VI doesn't perform any data reordering or padding. Data are not queued: each write operation with the same DEVILIndex overwrites the previous one.
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