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Some important choices or questions.

1. SLC CAMAC Magnet control and SLC BPM data acquisition by XAL Applications. The SLC CA server does not presently support "set" operations, so there is not presently a way for XAL applications, which use EPICS Ca through JCA, to change the value of CAMAC magents. Possible solutions are to add set to SLC CA, or to change XAL applications to use AIDA, or to accept that XAL applications can not control SLC CAMAC magnets -

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1. that would be bad for orbit correction for instance, since most magnets in the linac will be SLC control system. Similarly, the SLC-aware-IOC and EPICS BPM acquisition API will allow both an XAL based application, or the SCP, to acquire IOC hosted BPMs, but are there "classical" SLC BPMs that must be acquirable by XAL applications.
   

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   WindowsFilesystem WindowsFilesystem

2. Windows filesystem.
   If we do require native execution on Windows that decision should be made clearly and early, and resources assigned to implement the common executable and configuration file distribution so that Unix and Windows running applications are in sync and see the same configuration files. Java Web Start and Eclipse update site technology may be places to find solutions.
   

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   XAL_nocoupling XAL_nocoupling

3. XAL Plane Coupled modeling.
   The existing XAL probes for calculating R-matrices, run on either the X-plane or Y-plane and returns only a 2x2 matrix for each element. That is, it's uncoupled. This is reflected in the fact that only the Twiss parameters can be stored into an XAL file - it only contains uncoupled optics. It may be that XAL is in fact tracking a plane coupled system, but only returning the X or Y plane block-matrices - need to verify. So, if plane coupled orbit correction is important for us, we need to verify what XAL is doing, add at least 4x4 probe API, also probably also 6x6 tracking.
4. XAL Modelled acceleration and solenoid. XAL does not model acceleration nor solenoid field
5. Archiver. Which one?
6. XAL file generation directly from Oracle. Is there a mechanism to flag items in the oracle db for inclusion in the lattice? Danger is people will edit the Oracle db to say move an item to a new z location or include a dummy bpm, and the lattice will change.

REQUIRED ADDITIONS TO SLC CONTROL SYSTEM

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1. XAL http://www.sns.gov/APGroup/appProg/xal/xal.htm
2. XML entry in Wikipedia http://en.wikipedia.org/wiki/XML

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   ref_latticefiles ref_latticefiles

   LCLS lattice files http://www-ssrl.slac.stanford.edu/lcls/linac/optics/
4. JAMA http://math.nist.gov/javanumerics/jama/

5. Anchor
   ref_XAL_applications ref_XAL_applications

   http://www.diamond.ac.uk/CMSWeb/Downloads/diamond/Events/EPICS/XAL_Applications_Correlator_Framework.pdf

Answered Questions

This section lists questions that have been answered since the birth of this document.

1. Acquisition through JCA should also be verified, since the SLC BPM acqusition is oriented toward acquisitions of whole beamines and is highly parameterized.
   ANS: Diane (by Greg): the EPICS BPM API will largely mirror the SLC BPM API in that it will be oriented toward acquisitions of beamlines and allows specification of timing parameters. Greg: That's ok then as long as the setup required in an application is invariant whether it's talking to an SLC BPM through the SLCCAS (and if there is any requirement in LCLS apps to talk to SLC BPMs) or a new IOC hosted BPM.

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