Background
PV Data
Distributed Front-Ends
PCAS
Online Model
PCAS
Machine
CAC
PCAS
Virtual Accelerator
Client Applications
Middle LayerServers
Thin Application
CAC
CA V3
Thick Application
CAC
CA V3
CA V3 + PV Data
…
…
Primary Objective :
Basic Idea :
DDS Interface
http://sourceforge.net/projects/epics-dds
Benefits Brought by DDS to EPICS
The integration of these two technologies addresses five major tasks:
First, DDS brings an industrial standard interface to the accelerator online environment allowing to decouple a variety of high-level applications and toolkits from the underlying low-level control systems, such as EPICS, TINE, TANGO, and others.
Second, the DDS topic-oriented approach elevates the EPICS Channel Access protocol to the high-level applications replacing the additional RPC-like communication interfaces.
Third, DDS creates a basis of Service-Oriented Architecture (SOA) promoting decoupling of the service interfaces from their project-oriented implementations [Nanbor Wang, Tech-X Corp.]
Fourth, the DDS specification introduces some guidance for extending the EPICS infrastructure with the relevant set of quality of service.
Finally, the DDS technology extends the EPICS run-time environment with the relational model creating a platform for adding relational queries and integration of full-scale Data Stream Management Systems (DSMS) for data stream processing and archiving.
Major Milestones
June’ 08: Became aware of the OMG DDS after searching for “JMS C++”Sept’ 08: Checked it with OCI OpenDDS and PrismTech OpenSplicePVData meeting, BNL, Dec’ 08: Began the EPICS-DDS project implementingthe OMG DDS interface with the EPICS Channel Access protocol April’ 09: Replaced the DDS plain language binding with the PVData approachEPICS meeting, Spring’ 09: Introduced the EPICS-DDS project and conceptual ideas illustrated by a set of the dedicated examplesEPICS meeting, Fall’ 09: Built a prototype of a DDS-based high-level accelerator application environment including key middle layer servers, such as Machine, Online Model and Virtual Accelerator. Jan’ 10: Connected the EPICS-DDS middle layer with the Java client using the CAJ V3 and PVData of the EPICS-PVData projectFeb’ 10: Became an OMG Trial memberMarch – May’ 10: Commissioned the first EPICS-DDS application on the Cornell ERL injectorMay’ 10: Built the Model-Independent Analysis (MIA) composite application based on Online Model and Virtual Accelerator
Applications – 1 of 3
IOCIOC …
PCAS
Machine Server
CAC
NTMAT
load
PCAS
Turn-By-TurnServer
NTMAT
save
lattice file lattice file
Java Orbit Display
CAJ
CA
PVData
C. Gulliford, I. Bazarov, J. Dobbins, R. Talman (Cornell University), N. Malitsky (BNL)IPAC’10: THE NTMAT EPICS-DDS VIRTUAL ACCELERATOR FOR THE CORNELL ERL INJECTOR
PVData-based structures:• Machine Server Request• Turn-by-turn data
struct Position{ double x; double y;};struct TBTData { string name; vector<Position> tbt;};typedef vector<TBTData> TBTArray;
Applications – 2 of 3
PCAS
Machine Server
Java MIA Client
CAJCA
DDS Dynamic Data
PCAS
Twiss Server
PCAS
TBT Server
SVDMachine Publisher
CAC
PV Data
IPAC 10: APPLICATION OF MODEL INDEPENDENT ANALYSIS WITH EPICS-DDSN. Malitsky, I. Pinayev (BNL), R. Talman (Cornell U), C. Xiaomeng (Stony Brook University )
UALUALUAL
Applications – 3 of 3SBIR Grant: SERVICE-ORIENTED ARCHITECTURE FOR NEXT-GENERATION, LARGE-SCALE ACCELERATOR CONTROL SYSTEMSN. Wang (Tech-X Corp.)
Client
CACCA
PCAS
Optimization Server
MAD-X
PVData-based Optimization Request
PVData
Next : DDS Dynamic Topic Types
1. Data Distribution Service for Real-Time Systems, Version 1.2 formal 07-01-01, January 2007
2. Extensible Dynamic Topic Types for DDS RFP: June 27, 2008 Initial Submission: November 10, 2010 Revised Submission: February 22, 2010 Adopted Beta 1: May 21, 2010 Deadline for comments: November 29, 2010 FTF (Finalization Task Force) Recommendation and Report : April 4, 2011 Beta 2 (finalized specification): TBD