Wayne Lewis

Wayne Lewis

Australian Synchrotron

Beamline Controls Design and Implementation

March 2008 EPICS Collaboration Meeting, SSRF, Shanghai Wayne Lewis


Beamline Controls Design and Implementation

• Beamline summary• Resourcing• Technology decisions• Standards development• Infrastructure• Individual beamline implementations



Beamline summary

• Phase 1• Infrared Spectroscopy• Protein Crystallography• Powder Diffraction• X-ray Absorption

Spectroscopy• Soft X-ray Spectroscopy



Beamline summary

• Phase 2• Microspectroscopy• Imaging and Medical

Therapy• Small/Wide Angle

Scattering• Protein

Crystallography 2



Resourcing

• Staff• Development

equipment• External resources



Technology decisions - backgroundAccelerator controls

– EPICS controls throughout

– Standard PC based IOCs

– No use of VME

– GUI implemented in Delphi



Technology decisions - backgroundBeamline controls

• No pre-conceived ideas• Desire to use open source software• Desire to maintain consistency with existing

accelerator controls• Determine approach at comparable facilities and

beamlines• Desire to have single control system for all

beamlines



Technology decisions

Hardware• Off the shelf products• PC based IOCs• VME where essential

(using PCI/VME bridge)

• In-house motion control

• Protection systems



Technology decisions

Protections systems• Personnel protection• Equipment protection

Operating system• Avoid vxWorks• Use standard Linux

distributions• Determine need for real-

time OS



Technology decisions – control system software

• Six control systems reviewed• Selection criteria established• Candidates ranked• EPICS was the winner



Technology decisions – user interface software• Engineering/staff interface

• Use EPICS tools• Ease of use/speed of deployment

• Experimental user interface• No single right answer for all beamlines



Standards development

• Naming convention• IP addressing scheme• GUI standards• Motion control connectors• Coordinate system



Infrastructure

Network• Individual VLAN for each

beamline• EPICS gateway to accelerator

Personnel safety system• Same system as storage ring• PLC code developed in-house• Separate system for each

beamline• Carefully defined interfaces

between beamline and accelerator protection systems

Data storage



Powder diffraction

Experimental requirements• Single energy experiments• Multiple sample environments• Precision sample and detector positioning• Microstrip detector• High-resolution detectors• Scanning – step and on-the-fly• Relatively low data volume and rate• No well defined user interface preference



Powder diffractionPhoton delivery system

• Turnkey contract• Design, construction and supply of optics• Basic controls included in scope of supply• Equipment protection included in scope of supply• Controls involvement at all stages essential• Defined minimum EPICS releases to be used• Definition of interfaces and site standards• Close working relationship with controls vendor • Ongoing involvement through commissioning phase• 40 motors• 2 cameras, 1 equipment protection PLC• Beam condition and position monitoring



Powder diffraction

Endstation• Individual components

purchased separately• In-house integration

effort• In-house motion

controller• Close interaction with

detector supplier• Sample environments• 15 motors



Powder diffractionUser interface

• Using ‘xxx’ application from synApps

• Dedicated GUI for detector• EPICS ‘sscan’ record to

manage data collection• Detector controls modified

to be ‘EPICS-aware’



Powder diffractionEPICS usage

• Photon delivery system• Motion control• Cameras• Serial devices• PLC

• Endstation• Motion control• Scaler• Sample environment• Save/restore• Scan• PLC – Modbus• Digital IO• Multi-channel scaler



Powder diffractionNon-EPICS usage

• Microstrip detector• Analog/digital electronics• Embedded server• GUI is client• Sets up acquisition then reads out and saves data

Commissioning• External expert assistance

• Photon delivery system• Detector



Protein crystallography

Experimental requirements• Single energy experiments• Single sample environment• Well defined user interface• Commissioning endstation followed by final

endstation• Synchronisation of sample rotation and shutter• High data volume and rate• No scanning




Photon delivery system• Same as powder diffraction• Same vendor, very similar optics• 30 motors• 2 cameras• 2 beam position monitors• Equipment Protection PLC• Ion chamber




Endstation• Commissioning

endstation for twelve months

• CCD detector• Robotic sample

loading




Endstation• High speed shutter• High precision sample rotation• Cryogenic sample environment• Sample monitoring• Sample alignment• Sample visualisation• 22 motors• Energy dispersive detector• Data storage – 40TB




Control system• Mandate for

BluIce user interface

• Decide between SSRL and GMCA implementations




Comparison of SSRL and GMCA controls

BluIce

EPICS

Motors

Detector

Shutter

Robot

BluIce

DCSS

EPICS DHS

Motors

Shutter

Detector

Robot

GMCA SSRL




SSRL vs GMCA• SSRL benefits

• Use existing hardware drivers• Use existing scripted functions• Easier integration of specific hardware• Support from SSRL controls people• Minimal development work required• Can take advantages of updates from

SSRL

• GMCA benefits• “Simpler” architecture• No new control system to learn




EPICS usage• Photon delivery system

• Motion control• Cameras• Serial devices• PLC

• Endstation• Motion control



Protein crystallographyNon-EPICS usage

• Endstation• SSRL DCSS control system server• All experimental scripting• Screening database• Detector interface• Robot interface• MCA interface• User authentication• BluIce user interface• Motion control programs

Commissioning• External expert assistance

• Photon delivery system• Detector• SSRL controls



X-ray absorption spectroscopy

Experimental requirements• Energy scanning• Step scanning and on-the-fly

scanning• No well defined user interface• Basic energy dispersive

detector followed by multi-element detector

• Low data volume and rate• EXAFS and XANES

techniques




Photon delivery system• High-performance scanning monochromator• Cryogenic cooling system• 40 motors• Beam visualisation• Beam position control




Endstation• Single MCA detector• Multi-element Ge

detector• Multiple ion chambers




Endstation• Scanning is fundamental• Require both on-the-fly scans and

step scans• On-the-fly handled in hardware• Step scanning handled by EPICS

scan record



X-ray absorption spectroscopyEPICS usage

• Photon delivery system• Motion control• Serial devices• PLC

• Endstation• Motion control• Scanning• MCA• Digital IO• Analog IO• Scaler• Multi-channel scaling




EPICS usage• User interface

• MEDM• IDL – ScanSee• Python EXAFS scan front end



Summary

Turnkey contractsWork closely with contractorsDevelop standardsDevelop in-house experience and understandingCommon systems where possibleCustomise for experimental requirementsUse of external expertiseUse of EPICS makes much possible

Wayne Lewis

Documents

Transcript of Wayne Lewis