1. pvData,pvAccess,pvIOC,pvService Status EPICS Meeting June 2011 NSRRC,Hsinchu, Taiwan Marty Kraimer, Guobao Shen, and Matej Sekoranja

2. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 2 Outline of Talk What are pvData, pvAccess, pvIOC, pvService? – Brief description – Original implementations Java only – Current emphasis is C++ implementations. pvServiceCPP – Why C++ in addition to Java? – First services under development. Since EPICS meeting October 2010 at BNL, USA – pvDataCPP Implemented – pvAccessCPP Implemented pvIOCCP (C++ version of javaIOC) – pvAccess for V3 records implemented – Support for pvServiceCPP started – Full IOC in the future.

3. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 3 Accessing Source Code At this time no official releases – Must access via sourceforge project epics-pvdata Java: pvData, pvAccess, javaIOC, pvService – Developed as Eclipse projects – Currently CVS. Later Mercurial. Host: epics-pvdata.cvs.sourceforge.net Repository Path: cvsroot/epics-pvdata Modules: pvData, pvAccess, javaIOC pvService – javaDoc: project and package overview pvDataCPP, pvAccessCPP,pvIOCCP,pvServiceCPP – All developed as EPICS V3 base applications – EPICS build system and libCom – Mercurial – epics-pvdata.hg.sourceforge.net/hgroot/epics-pvdata/ pvDataCPP pvAccessCPP pvIOCCP pvServiceCPP

4. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 4 pvData, pvAccess, pvIOC,pvService pvData  Memory resident structured data  Introspection and Data interfaces  Client sees top level PVStructure pvAccess – Network support for pvData javaIOC ( old name for pvIOC) – PVRecord + database of PVRecords – Record Scanning – Periodic and Event – support – no distinction between record and device support any field can optionally have associated support standard: alarm, timeStamp, scan etc. extensible – Can be used wherever appropriate pvService – Service layer for High Level Applications – itemFinder, gather, model server, etc.

5. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 5 Services Service layer for High Level Application  Client/server model  pvData/pvAccess for communication between client and server itemFinder Service – Given a search string return a list of channel names and properties createGather Service – Given a list of channels create a new gather record gather Service – Get/put/monitor a set of channels – Examples: BPMs for a bump or golden orbit Correctors for a bump or golden orbit Model server – Interface to model server: Elegant, etc.

6. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 6 Many Services Require C++ Interface to C/C++ Accelerator Modeling Codes Services in a V3 IOC Support for Python (not Jython) – numPY – itemFinder interface to IRMIS; Python nicest interface to IRMIS Two example Accelerator Applications are shown on the next two slides

7. Twiss Service Example Twiss service Get beam parameters from/into IRMIS database Lattice information (geometric + magnetic strength) Model information for each calculation based on lattice Elements included in each model Calculated beam parameters (optics, transfer map (6x6 metric), tune, chrom..) Structure data thru scalarArray Client Server RDB Server

8. Orbit Service Example Orbit service Get beam orbit from EPICS V3 IOC Structure data thru a scalarArray X, Y, TS, Status, Position... Using Python/Channel Access Same architecture to serve data from data sources (V3 IOC or IRMIS) Easy data manipulation (re-structure data, and so on) Client Server EPICS IOC

9. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 9 pvDataCPP and pvAccessCPP Both have been implemented Client testing: – A javaIOC is started with the pvAccess client running – The javaIOC swtshell is used to connect to V3 records Server testing is via a pvIOCCP – A database of V3 records is provided – The v3Channel support is started via the st.cmd file Testing as above demonstrates that: – A java pvAccess client talks to a C++ pvAccess server. All communication between client and server is via pvAccess

10. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 10 pvIOCCP C++ implementation of a V4 IOC. v3Channel implements Channel interface to V3 records – pvAccess remote server talks to v3Channel V4 database, V4 Records, Scanning, Support – Basic interfaces defined But not portDriver (asynDriver) – Only a few implemented – Nothing tested – Lots of work for the future Support for services under development – Base classes for Channel and Channel Provider Channel access interface for services – Other help for services Because V4 database, etc not available

11. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 11 Channel A connection between client and channelName Methods – getField: returns introspection interface – createChannelGet, channelGet – createPut, channelPut – createChannelPutGet, channelPutGet – createChannelRPC, channelRPC – createMonitor, monitor – createChannelArray, channelArray (subarray) Local and remote Top level pvStructure passes between client and server Remote pvAccess server allows multiple providers – each implements Provider and Channel – remote server talks to Channel

12. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 12 v3Channel Implements interface Channel Can be accessed directly by local pvAccess client Is a ChannelProvider for server side of remote pvAccess Provides access to V3 records, i.e. EPICS records V3 record appears as a structured set of fields – V3 record instance looks like a top level pvStructure Supports: getField, process, get, put, monitor, array – putGet, channelRPC do not apply to V3 records. Access is via dbAccess, recSup, etc – Thus direct access to record instead of via CAV3 – Exception is monitor db_post_event implemented by dbEvent (implement by CAV3) CAV3 monitor only for scalars, stat, sevr, and timeStamp For others after monitor event access via dbAccess, recSup

13. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 13 pVAccess view of V3 record record double01 double value 2.0 structure alarm severity major message LOLO timeStamp 2011-04-13 06:56:06.932 structure display string description string format %f string units Counts structure limit double low 0.0 double high 10.0 structure control structure limit double low -0.1 double high 9.9 double minStep 0.0

14. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 14 Support For Services In javaIOC Support provided via – Support attached to some field of the support record – Get, put, etc, handled via standard javaIOC support – Support normally accessed via put/process/get But standard support not ready so for now: – Provide base class that handles get, put, monitor, etc. – Support only needs to implement putProcessGet Work in progress

15. NSRRC,Hsinchu, Taiwan, June 2011pvData,pvAccess,javaIOC,pvServic e 15 Vision For Future Implement all of what is in javIOC in pvIOCCPP JavaIOC portDriver provides functionality of asynManager but better – BUT Almost no portDrivers No synApps No area detector Etc etc Sigh!! When portDriver is implemented in pvIOCCP – Can use all existing portDrivers – Can use lots of area detector – Can use lots of synAPPs – Can provide structured data to/from portDriver clients!!!!!