MACHINE
LAYOUT
COORDINATION
Project
Document Type
Life Cycle
Author
Version
Title:
High Level Control System
Specification
Document Number
Draft
Josef Wilgen
Affiliation
0.2
Date
2012-09-04
BLM Middle Layer Server Specification
Introduction
The BLM Middle Layer server is a complement to the DAQ. It runs on the DAQ server
and processes BLM data which are sampled via the DAQ event mechanism. The results
are made available through a DOOCS interface.
Concept
The BLM Server takes incoming data samples via shared memory from the DAQ. It uses
the DAQs event mechanism to access each event’s BLM data. Since it is not possible to
access older data sets in the shared memory, the BLM ML Server needs to store the sampled data itself. A certain number of data sets is stored in memory and a storage on disk
may be needed in order to initialize the buffer in case of a restart. The maximal depth of
the buffer needs to be determined.
The BLM ML server has the task to provide clients with processed data for a selected set
of BLMs. For instance, it provides the losses averaged over time or over all bunches.
The BLM ML server uses the DDAQ Library from Olaf Hensler. It is desirable to build
up the BLM ML according to a standard structure for such servers, as far as possible.
How the standard structure matches to the client’s requirements has to be determined.
The requirements from the client side are described in the MATLAB Middle Layer
Specification.
Properties
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BEAMLOSS.TD (Spectrum) Beam losses over time for one bunch train.
BEAMLOSS_AVG (float) Average of BEAMLOSS.TD.
BEAMLOSS_MAX (float) Maximum of BEAMLOSS.TD.
BEAMLOSS_RMS (float) RMS value of BEAMLOSS.TD.
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BEAMLOSS_BUNCHCUR.TD (Spectrum) Beam losses over time for a bunch
train, containing only values which belong to bunch current.
BEAMLOSS_BUNCHCUR_AVG (float) Average of
BEAMLOSS_BUNCHCUR.TD
BEAMLOSS_BUNCHCUR_MAX (float) Maximum of
BEAMLOSS_BUNCHCUR.TD.
BEAMLOSS_BUNCHCUR_RMS (float) RMS value of
BEAMLOSS_BUNCHCUR.TD.
BEAMLOSS_DARKCUR.TD (Spectrum) Beam losses over time for a bunch
train, containing only values which belong to dark current.
BEAMLOSS_DARKCUR_AVG (float) Average of
BEAMLOSS_DARKCUR.TD.
BEAMLOSS_DARKCUR_MAX (float) Maximum of
BEAMLOSS_DARKCUR.TD.
BEAMLOSS_DARKCUR_RMS (float) RMS value of
BEAMLOSS_DARKCUR.TD.
BEAMLOSS_MEAN.TD (Spectrum) Mean value of each bunch over time,
lowpass-filtered.
BEAMLOSS_RMS.TD RMS (Spectrum) RMS value of each bunch over time.
BEAMLOSS_MEAN_OF (Spectrum, input int) Mean value of n last beam loss
samples, where 1 <= n <= 100.
BEAMLOSS_PEAK.TD Peak-hold of beam loss over time with adjustable
decay.
LOWPASS_CUTOFF_FREQ Relative cutoff frequency of lowpass filter
(default 0.01)
PEAKHOLD_DECAY Decay factor of peak hold (y[n] = decay * y[n-1])