JavaIOC Status EPICS Meeting ICALEPCS2009 Kobe Japan Marty Kraimer And Matej Sekoranja

1. JavaIOC StatusEPICS Meeting ICALEPCS2009 Kobe JapanMarty Kraimer And Matej Sekoranja

2. ICALEPCS EPICS Meeting: javaIOC Outline of Talk • What is javaIOC? • New features since Vancouver EPICS meeting • Overview of pvData • Overview of javaIOC • Examples of VDCT in action • CAJv4 – Channel Access for Java Version 4

3. ICALEPCS EPICS Meeting: javaIOC JavaIOC: What is it? • EPICS IOC record has • flat structure – VAL plus other fields • channel access – value, alarm, timeStamp, display, control • dbCommon – support handled by dbAccess, etc. • DTYP, INP/OUT – support done by device support • recordType – support for all other fields done by record support • JavaIOC record has • structured data – record can be a device. example is a power supply • channel access – full support for structure data • structures • standard: alarm, timeStamp, display, control • extensible – can be application specific but supported by CA • support – no distinction between record and device support • any field can optionally have associated support • standard: alarm, timeStamp, linearConvert, digital, etc • extensible – Can be used wherever appropriate • PVData has many other possible uses

4. ICALEPCS EPICS Meeting: javaIOC Example Record Instances <record name = "valueOnly"> <scalar name = "value" scalarType = "double">1.0</scalar> </record> <record name = "valueAlarmTimeStamp"> <scalar name = "value" scalarType = "double"/> <structure name = "alarm" extends = "alarm" /> <structure name = "timeStamp" extends = "timeStamp" /> </record> <record name = "aiExample"> <scalar name = "value" scalarType = "double"/> <structure name = "alarm" extends = "alarm" /> <structure name = "timeStamp" extends = "timeStamp" /> <structure name = "link" extends = "caInputLink"> <scalar name = "pvname">somePV</scalar> </structure> </record>

5. ICALEPCS EPICS Meeting: javaIOC Example Record: Power Supply • Additional fields may also be present. powerSupply alarm timeStamp power value alarm voltage value alarm input ... current value alarm output ...

6. ICALEPCS EPICS Meeting: javaIOC Main New Features • CHANNEL ACCESS!!! • Full network support for pvData • CAJv4 implemented by Matej • Two new packages for pvData: pvCopy and monitor. • VDCT!! • Implemented by Janez Golob and Jernej Fesel Kamenick (CosyLab)‏ • Special Thanks to: • Bob Dalesio for support, advice, and encouragement • Guobao Shen (BNL) who is implementing first High Level Implementation. Talk later today. • Sheng Peng (SLAC) who is defining structures and implementing support that is similar to the recordTypes in EPICS base.

7. ICALEPCS EPICS Meeting: javaIOC epics-pvdata • EPICS-pvdata is a Source Forge Project (sourceforge.net)‏ • PVData is being developed as eclipse projects • pvData – memory resident database – records have structured data • CAJv4 – Channel Access for Java Version 4 • javaIOC – Record Processing and Optional Support for fields • Others – Not discussed in this talk • A link in the sourceforge summary provides: • An overview of EPICS-pvData. • Links to the javaDoc for pvData, CAJv4, and javaIOC. • Each eclipse project has a project overview. • Many eclipse packages have a package overview. • Release 0.8.0 is available. • Instructions for importing as eclipse projects. • .8 means that most functionality implemented and lots of testing has been done. • 0.8 means that future 0.x.x releases will not guarantee compatibility

8. ICALEPCS EPICS Meeting: javaIOC pvData • PVDatabase – Memory Resident Database of PVRecords. • PVRecord – Is a top level PVStructure. • PVStructure – Is a structured set of PVFields. • PVField • Has a type : scalar, array, or structure. • Contains data. • Has code for accessing data and for introspection. • Accessed via Java interfaces • Any field of any record can be monitored for puts. • New since Vancouver. • New package pvCopy. • Copy of an arbitrary subset of the fields in a PVRecord. • Optionally share the data from the PVRecord. • New package monitor. • Extensible monitor implementation

9. ICALEPCS EPICS Meeting: javaIOC New pvData packages that support caV4 • org.epics.pvData.pvCopy • PVCopy – An interface for a PVStructure. • Accesses an arbitrary subset of the fields in a PVRecord. • Can optionally share the data from the PVRecord. • PVCopyMonitor – An interface for monitoring a PVRecord. • Updates the fields in PVCopy. • Updates two BitSets (a bit per field): change and overrun. • org.epics.pvData.monitor • Monitor Queue • Client chooses queue size • 0 no queue and share data with record • 1 no queue but single copy • >=2 queue size • Monitor Algorithm • Identified by name • Provided: onPut, onChange, onAbsoluteChange,onPercentChange • Extensible • Implementation • Registers during initialization.

10. ICALEPCS EPICS Meeting: javaIOC javaIOC • Main Features: • A record can be processed. • Each field can optionally have associated support. • PortDriver is java implementation of asynDriver. • Almost no low level driver support. Thus not ready. • swtshell - Standard Widget Toolkit shell for a javaIOC. • Full support for channel access. • Changes since Vancouver. • Only channel access related changes. • org.epics.ioc.ca - Old definitions for channel access. • Deleted • In CAJv4 • Very different. Lighter weight.

11. ICALEPCS EPICS Meeting: javaIOC VDCT • VDCT - Visual Database Configuration Tool • based on Java NetBeans Visual Library • generic data model, support for EPICS V3 and V4 implemented • 'standard' GUI features: clipboard, undo/redo, drag & drop, etc. • views: graphical, property (inspector), spreadsheet, tree • customizable record shapes and colors (CapFast-like shapes implemented)‏ • file-system and basic IRMIS support • Next four slides show VDCT in action

12. ICALEPCS EPICS Meeting: javaIOC EPICS V4 Record

13. ICALEPCS EPICS Meeting: javaIOC V4 Hierarchy

14. ICALEPCS EPICS Meeting: javaIOC EPICS V3 Record

15. ICALEPCS EPICS Meeting: javaIOC V3 Spread Sheet

16. ICALEPCS EPICS Meeting: javaIOC Channel Access Overview • Eclipse project CAJv4 • Full support for pvData. • Depends only on project pvData. • Three components can be started by an application. • ClientFactory.start() - client side of network support. • LocalFactory.start() - access local PVDatabase. • ServerFactory.start() - server side of network support. • org.epics.ioc.caV3 ( In javaIOC; May become separate eclipse project)‏ • Has been available for couple of years. • Client support • Allows a pvData client to access EPICS V3 Data. • Server support • Allows an EPICS V3 CA client to access a PVDatabase. • Other Channel Providers can be registered. • Gateways to/from other data sources. • An application can start all of the above.

17. ICALEPCS EPICS Meeting: javaIOC Connecting to a Channel • ChannelAccessFactory returns ChannelAccess. • Given a provider name ChannelAccess returns the ChannelProvider. • providers local, caV3, and caV4 are implemented • Given a channel name ChannelProvider creates a Channel. • A Channel connects the client to a PVRecord.

18. ICALEPCS EPICS Meeting: javaIOC Channel Methods • destroy – Disconnect and clean up. • utility • isConnected, getChannelName, ... • introspection • getField – shown on next slide • Creation - Create once. Request may times without object creation. • createChannelProcess – process a record. • createChannelGet – get data from a record. • createChannelPut – put data to a record. • createChannelPutGet – put followed by get • createMonitor - monitor a record. • createChannelArray – get/put sub-array. • Remainder of talk shows introspection, get, and, putGet.

19. ICALEPCS EPICS Meeting: javaIOC Introspection • Client calls channel.getField. • channel.getField(this,null) - get introspection interface for record. • channel.getField(this,”value”) - get introspection interface for value. • channel.getfield(this,”display.limit”) - can get subfields. • Client implements GetFieldRequester. • getDone returns • status – next slide • field – The introspection interface. //interface Channel has method void getField(GetFieldRequester requester,String subField); // client implements public interface GetFieldRequester extends Requester { void getDone(Status status,Field field); }

20. ICALEPCS EPICS Meeting: javaIOC Status • Methods report success/failure via interface Status • Defined in pvData.pv • Status type is one of OK,WARNING,ERROR,FATAL • Methods provide • The status type • An optional message string • An optional stack dump • isOK • Status is a singleton, i. e. no object creation for success. • This is normal return value. • isSuccess

21. ICALEPCS EPICS Meeting: javaIOC Get Semantics

22. ICALEPCS EPICS Meeting: javaIOC createChannelGet arguments • channelGetRequester – implemented by client. Methods are: • channelGetConnect - called after ChannelGet is created by server • getDone - called when a get completes. Get is a method of ChannelGet • pvRequest – next slide. • structureName – name given to PVStructure created for client. • shareData – Should server share data with the PVRecord. • for arrays can save memory. • for display managers good enough. • process • process record before getting data. • pvOption • for a client to pass extra information to a server. • client and server must agree on structure. • can be null for most except createMonitor.

23. ICALEPCS EPICS Meeting: javaIOC pvRequest structure • Defines the set of fields to which to connect. • Client must create this. Not trivial!! • Can create via xml definition or pvData factory • BUT there is also an easier way. ChannelAccess has a method which accepts a string argument and returns a pvRequest structure. Examples: • ”value,alarm,display” • This attaches to top level fields with the same names • The following request gets the following from a power supply record: alarm and timeStamp from the record and value and alarm for the power, voltage, and current. "alarm,timeStamp" + ",power{power.value,power.alarm}" + ",current{current.value,current.alarm}" + ",voltage{voltage.value,voltage.alarm}");

24. ICALEPCS EPICS Meeting: javaIOC channelPutGet • This does a put, an optional process, and a get. • A javaIOC has a set of RPC (Remote Procedure Call) records. • Each has a structure named arguments. • Each has a support that implements the RPC semantics. • Each has a structure named result which hold the result data. • recordListRPC • argument is a regular expression. • result is the names of all the records that match. • iocShowRPC • argument is a command that defines what to show. • result depends on command. • recordShowRPC • arguments are a record name and command. • result depends on command.

25. ICALEPCS EPICS Meeting: javaIOC Important Remaining Tasks • Access Security • Not Implemented. A complication is that a channel does not attach to a single field. • Query Facility • Nothing has been implemented. • TCP Transport • Currently sender asks for network buffer, puts data, releases • Can not send more than fits in a network buffer. • Will be changed • Sender queues request to send. • Gets exclusive access to network port. • Can issue multiple sends. • Serialization will be changed. It can trigger network send. • No need for big network buffers just use MTU of network.