This project provides a set of examples of client and server code for pvAccess. Each example can be built separately by building in the example subdirectory. The complete set of examples, except for ChannelArchiverService can also be built by building in exampleCPP itself.

Each example can be used as a template for building other applications:

• Choose an example that is similar to the desired application.
• Copy the complete example to where the desired application should reside.
• Edit the new application.

There is also a test that supports:

make runtests

This test requires that at least database is built.

This is only a good idea if a proper RELEASE.local is present one directory level above exampleCPP.

Just type:

make

An example of a proper RELEASE.local is:

EPICS4_DIR=/home/epicsv4/master
EXAMPLE=${EPICS4_DIR}/exampleCPP
PVDATABASE=${EPICS4_DIR}/pvDatabaseCPP
PVACLIENT=${EPICS4_DIR}/pvaClientCPP
PVASRV=${EPICS4_DIR}/pvaSrv
PVACCESS=${EPICS4_DIR}/pvAccessCPP
NORMATIVETYPES=${EPICS4_DIR}/normativeTypesCPP
PVDATA=${EPICS4_DIR}/pvDataCPP
PVCOMMON=${EPICS4_DIR}/pvCommonCPP
EPICS_BASE=/home/install/epics/base

All examples can also be built by:

cp configure/ExampleRELEASE.local configure/RELEASE.local
edit file configure/RELEASE.local
make

In configure/RELEASE.local it may only be necessary to change the definitions of EPICS4_DIR and EPICS_BASE.

If a proper RELEASE.local is present one directory level above exampleCPP then in the example directory just type:

make

Each example has a README.md file. See it for how to build the example if a proper RELEASE.local does not exist or if the example has special requirements.

A very simple example of an EPICS V4 RPC service: This implements a "Hello World" example of a service that is accessed via Channel RPC.

This is a good starting point for writing an RPC service.

The ChannelArchiver Service is an EPICS V4 client and server which can be used to query the data archived by an EPICS Channel Archiver. It includes a bash script, gethist, which can parse a wide range of dates and times and process the corresponding data. However the service can be queried by any client issuing a pvAccess RPC request, such as eget. Requests and responses use EPICS V4 normative types. Requests are in the form of an NTURI normative type and the results are returned as an NTTable.

Provides an EPICS IOC that has both EPICS V3 DBRecords, V4 PVRecords, and pvaSrv for accessing the DBRecords.

It can also create a standalone main that has a set of V4 PVRecords.

Provides a set of examples that use pvaClientCPP.

In order to run the examples, database must also be built and then the IOC database must be started as follows:

mrk> pwd
/home/epicsv4/master/exampleCPP/database/iocBoot/exampleDatabase
mrk> ../../bin/$EPICS_HOST_ARCH/exampleDatabase st.cmd

An example of a PVRecord that implements a "Hello World" service that can be accessed via ChannelPutGet.

An example of a pvDatabase PVRecord which also supports RPC services.

The record represents a 2-D position, but also provides an RPC service which moves the position through a sequence of points before returning. A channel to the record supports the usual operations (such as get, put and monitor) but also supports Channel RPC, i.e. the RPC service has the same channel name as the position PV.

A client ("move") for calling the service is supplied.

This implements a V3 IOC that has a PVRecord doubleArray and a PVRecord exampleLink that monitors changes to doubleArray. PVRecord exampleLink uses pvAccess client code to monitor for changes in doubleArray. It can use either provider local or pva to connect to doubleArray.

This is an example of creating a PVRecord that uses a somewhat complicated top level PVStructure. It simulates a power supply.

The example also has an example pvaClient for accessing the PVRecord.

This is an example that shows performance for an array of longs.

arrayPerformanceMain implements a PVRecord that is a long array. It has a process method with code that causes the array to be updated at selectable rates and sizes!

It also has pvaClient examples that can get, put and monitor the long array record.

This is not an embeded top level but just a subdirectory of exampleCPP.

This is an example that tests pvDatabase and pvaClient.
This example requires that database must also be built.

It is meant to be used to execute:

make runtests

When this is done it starts the example database and then executes various client tests.