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added support for privider ca; many minor changes; note exampleDatabaseEasyPVA.zip changed

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Marty Kraimer
2015-03-25 10:38:22 -04:00
parent 6a351cb5a2
commit 6b6f4bd2a9
15 changed files with 575 additions and 29 deletions
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documentation/easyPVA.html
+67 -14
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@@ -28,14 +28,16 @@
<h1>EPICS easyPVA</h1>
<!-- Maturity: Working Draft or Request for Comments, or Recommendation, and date. -->
<h2 class="nocount">EPICS V4 Working Group, Working Draft,
13-Mar-2015</h2>
25-Mar-2015</h2>
<dl>
<dt>This version:</dt>
<dd><a
href="easyPVA.html">easyPVA.html
</a> </dd>
<dt>Latest version:</dt>
<dd>none</dd>
<dd><a
href="easyPVA_20150325.html">easyPVA_20150325.html</a>
</dd>
<dt>Previous version:</dt>
<dd>none</dd>
<dt>Editors:</dt>
@@ -61,12 +63,13 @@ scalar and scalarArray data types.
Additional methods provide access to the full features of pvAccess.
</p>
<p>
EasyMultiChannel provides access to data from multiple channels as long
as each channel has a top level field named <b>value</b>.
EasyMultiChannel provides two ways to access data from multiple channels:
The first is as an NTMultiChannel. The second is as a double array.
The double array can be used if the value field of every channel is a numeric scalar.
There is code for NTMultiChannel that helps with access to more complicated data types.
EasyMultiChannel provides access to data from multiple channels.
It can be used directly by a client or via EasyMultiDouble or EasyNTMultiChannel.
EasyMultiDouble allows the client to get and put data to multiple channels.
But each channel must have a value field that is a numeric scalar.
EasyNTMultiChannel allows the client to get and put data to multiple channels.
Each channel must have a value field.
The data for the channels is presented via normative type NTMultiChannel.
</p>
<!-- last para of Abstract is boilerplate reference to EPICS -->
<p>For more information about EPICS generally, please refer to the home page of the <a
@@ -77,7 +80,7 @@ There is code for NTMultiChannel that helps with access to more complicated data
<h2 class="nocount">Status of this Document and of the EasyPVA Software</h2>
<p>Under development</p>
<p>EasyPVACPP is ready for use.</p>
</div> <!-- head -->
@@ -98,7 +101,7 @@ an interface to many of the features provided by pvData and pvAccess.</p>
<p>
A user overview is available via
<a
href="./overiew.html">overview.html
href="./overview.html">overview.html
</a>
</p>
<p>
@@ -123,7 +126,7 @@ make
</pre>
<h2>Example and Test Database</h2>
<p>The examples require that an example pvAccess server is runnimg.
<p>The examples and tests require that an example pvAccess server is runnimg.
This distribution has a file <b>exampleDatabaseEasyPVA.zip</b>.
When unzipped this is used to create an example IOC database.
The database has the record used by the examples are tests that come with easyPVAJava.
@@ -155,10 +158,60 @@ mrk&gt; pwd
/home/hg/easyPVACPP/example
mrk&gt; bin/linux-x86_64/exampleEasyGet
</pre>
<p>
See the source code for each example.
<p>The following is a brief description of each example.
In order to understand each example it
helps to also bee loooking at the source for the example.</p>
<h2>exampleEasyGet</h2>
<p>This has a number of examples:</p>
<dl>
<dt>exampleDouble</dt>
<dd>
This shows two methods for getting data from a channel that has a numeric
scalar value field.
</dd>
<dt>exampleDoubleArray</dt>
<dd>
This shows two methods for getting data from a channel that has a
double array value field.
</dd>
<dt>exampleCADouble</dt>
<dd>
This is like exampleDouble except it uses provider <b>ca</b>.
</dd>
<dt>exampleCADoubleArray</dt>
<dd>
This is like exampleDoubleArray except it uses provider <b>ca</b>.
</dd>
<dt>examplePowerSupply</dt>
<dd>
This is an example of getting data from a channel that does not
have a value field.
</dd>
</dl>
<h2>exampleEasyMonitor</h2>
<p>This is an example of creating a monitor on a channel.
It monitors a channel that models a powerSupply, i. e. it is not a "standard" record.
It does not have a value field.
</p>
<p>After starting the example a change can be made to the powerSupply by issuing:</p>
<pre>
pvput -r "power.value,voltage.value" examplePowerSupply 6 6
</pre>
<h2>exampleEasyPut</h2>
<p>This example gets and puts to channel exampleDouble.</p>
<h2>exampleEasyProcess</h2>
<p>This example makes a process request to channel exampleDouble.</p>
<h2>helloWorldPutGet</h2>
<p>This is an example of issuing a channelPutGet.</p>
<h2>exampleEasyMultiDouble</h2>
<p>This is an example of issuing gets and puts to multiple channels where each
channel has a numeric scalar value field.</p>
<h2>exampleEasyNTMultiChannel</h2>
<p>This is an example of using NDMultiChannel to obtain data from multiple channels.
</p>
<h2>helloWorldRPC</h2>
<p>This is an example of issuing a channelRPC request.
It does <b>not</b> use easyPVA.</p>
</div> <!-- class="contents" -->
</body>
</html>
documentation/easyPVA_20150325.html
+217
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@@ -0,0 +1,217 @@
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
<title>EPICS easyPVA</title>
<link rel="stylesheet" type="text/css"
href="http://epics-pvdata.sourceforge.net/base.css" />
<link rel="stylesheet" type="text/css"
href="http://epics-pvdata.sourceforge.net/epicsv4.css" />
<style type="text/css">
/*<![CDATA[*/
.about { margin-left: 3em; margin-right: 3em; font-size: .83em}
table { margin-left: auto; margin-right: auto }
.diagram { text-align: center; margin: 2.5em 0 }
body { margin-right: 10% }
/*]]>*/</style>
<!-- Script that generates the Table of Contents -->
<script type="text/javascript" src="http://epics-pvdata.sourceforge.net/script/tocgen.js"></script>
</head>
<body>
<div class="head">
<h1>EPICS easyPVA</h1>
<!-- Maturity: Working Draft or Request for Comments, or Recommendation, and date. -->
<h2 class="nocount">EPICS V4 Working Group, Working Draft,
25-Mar-2015</h2>
<dl>
<dt>This version:</dt>
<dd><a
href="easyPVA.html">easyPVA.html
</a> </dd>
<dt>Latest version:</dt>
<dd><a
href="easyPVA_20150325.html">easyPVA_20150325.html</a>
</dd>
<dt>Previous version:</dt>
<dd>none</dd>
<dt>Editors:</dt>
<dd>Marty Kraimer, BNL</dd>
<dd>Matej Sekoranja, Cosylab</dd>
</dl>
<h2 class="nocount">Abstract</h2>
<p>EasyPVA (Easy PVAccess) is a software library that provides to an EPICS client programmer, a friendly
client side programming interface to the data of an EPICS based control system. It is intended
for such uses as rapid development of ad hoc programs by controls engineers, or to provide
scientists a way to directly develop analytical applications.</p>
<p>Specifically, easyPVA provides an easy interface for pvAccess, which is the
software support for high speed controls network communications used in EPICS version 4.
PvAccess provides a callback based interface, which can be hard to use.
EasyPVA provides an interface that does not require callbacks even for monitors.
</p>
<p>
EasyChannel provides many "convenience" methods to directly get and put
scalar and scalarArray data types.
Additional methods provide access to the full features of pvAccess.
</p>
<p>
EasyMultiChannel provides access to data from multiple channels.
It can be used directly by a client or via EasyMultiDouble or EasyNTMultiChannel.
EasyMultiDouble allows the client to get and put data to multiple channels.
But each channel must have a value field that is a numeric scalar.
EasyNTMultiChannel allows the client to get and put data to multiple channels.
Each channel must have a value field.
The data for the channels is presented via normative type NTMultiChannel.
</p>
<!-- last para of Abstract is boilerplate reference to EPICS -->
<p>For more information about EPICS generally, please refer to the home page of the <a
href="http://www.aps.anl.gov/epics/">Experimental Physics and Industrial
Control System</a>.</p>
<h2 class="nocount">Status of this Document and of the EasyPVA Software</h2>
<p>EasyPVACPP is ready for use.</p>
</div> <!-- head -->
<div id="toc">
<h2 class="nocount">Table of Contents</h2>
</div>
<!-- Place what you would like in the Table of Contents, inside the contents div -->
<div id="contents" class="contents">
<hr />
<h2>Introduction</h2>
<p>EasyPVA is a synchronous API for accessing PVData via PVAccess. It provides
an interface to many of the features provided by pvData and pvAccess.</p>
<p>This document describes the layout of the source files in this project.</p>
<p>
A user overview is available via
<a
href="./overview.html">overview.html
</a>
</p>
<p>
Doxygen documentation is available at
<a
href="./html/index.html">doxygenDoc
</a>
</p>
<h2>Building</h2>
<p>After obtaining the source:</p>
<pre>
cd configure
cp ExampleRELEASE.local RELEASE.local
</pre>
<p>Edit <b>RELEASE.local</b> so that all path names are correct for you environment.
</p>
<p>
Then:</p>
<pre>
cd ..
make
</pre>
<h2>Example and Test Database</h2>
<p>The examples and tests require that an example pvAccess server is runnimg.
This distribution has a file <b>exampleDatabaseEasyPVA.zip</b>.
When unzipped this is used to create an example IOC database.
The database has the record used by the examples are tests that come with easyPVAJava.
It uses pvDatabaseCPP to build the database.
</p>
<p>
After unzipping the file:
</p>
<pre>
cd configure
cp ExampleRELEASE.local RELEASE.local
edit RELEASE.local
cd ..
make
cd iocBoot/exampleDatabase
../../bin/&lt;arch:&gt;/exampleDatabase st.cmd
</pre>
<h2>Testing</h2>
<p>The tests will fail unless the example database is running.</p>
<p>Once it is running:</p>
<pre>
make runtests
</pre>
<h2>Examples</h2>
<p>Examples are in directory <b>example/src</b>.
An example of how to run them is:</p>
<pre>
mrk&gt; pwd
/home/hg/easyPVACPP/example
mrk&gt; bin/linux-x86_64/exampleEasyGet
</pre>
<p>The following is a brief description of each example.
In order to understand each example it
helps to also bee loooking at the source for the example.</p>
<h2>exampleEasyGet</h2>
<p>This has a number of examples:</p>
<dl>
<dt>exampleDouble</dt>
<dd>
This shows two methods for getting data from a channel that has a numeric
scalar value field.
</dd>
<dt>exampleDoubleArray</dt>
<dd>
This shows two methods for getting data from a channel that has a
double array value field.
</dd>
<dt>exampleCADouble</dt>
<dd>
This is like exampleDouble except it uses provider <b>ca</b>.
</dd>
<dt>exampleCADoubleArray</dt>
<dd>
This is like exampleDoubleArray except it uses provider <b>ca</b>.
</dd>
<dt>examplePowerSupply</dt>
<dd>
This is an example of getting data from a channel that does not
have a value field.
</dd>
</dl>
<h2>exampleEasyMonitor</h2>
<p>This is an example of creating a monitor on a channel.
It monitors a channel that models a powerSupply, i. e. it is not a "standard" record.
It does not have a value field.
</p>
<p>After starting the example a change can be made to the powerSupply by issuing:</p>
<pre>
pvput -r "power.value,voltage.value" examplePowerSupply 6 6
</pre>
<h2>exampleEasyPut</h2>
<p>This example gets and puts to channel exampleDouble.</p>
<h2>exampleEasyProcess</h2>
<p>This example makes a process request to channel exampleDouble.</p>
<h2>helloWorldPutGet</h2>
<p>This is an example of issuing a channelPutGet.</p>
<h2>exampleEasyMultiDouble</h2>
<p>This is an example of issuing gets and puts to multiple channels where each
channel has a numeric scalar value field.</p>
<h2>exampleEasyNTMultiChannel</h2>
<p>This is an example of using NDMultiChannel to obtain data from multiple channels.
</p>
<h2>helloWorldRPC</h2>
<p>This is an example of issuing a channelRPC request.
It does <b>not</b> use easyPVA.</p>
</div> <!-- class="contents" -->
</body>
</html>
documentation/overview.html
+18 -10
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@@ -84,6 +84,16 @@ EasyProcessPtr process = channel-&gt;createProcess();
process-&gt;process();
</pre>
<p><b>easyPVACPP</b> includes a number of examples.</p>
<p>easyPVA does <b>not</b> provide support for:</p>
<dl>
<dt>ChannelArray</dt>
<dd>TBD</dd>
<dt>ChannelRPC</dt>
<dd>pvAccess itself already provides an easy to use synchronous interface.
The examples include helloWorldRPC, which is an example of using channelRP.
</dd>
</dl>
<h2>EasyPVA</h2>
<p>An instance of EasyPVA is obtained via the call:</p>
@@ -94,10 +104,9 @@ EasyPVAPtr easyPVA = EasyPVA::create();
<p>EasyPVA has methods to create instances of <b>EasyChannel</b>.
The client can specify the provider name or use the default provider.
The client can manage it's own channels or can let easyPVA cache channels.
An example of using the cache method is:</p>
An example of using the cached method is:</p>
<pre>
string channelName("exampleDouble");
EasyChannelPtr easyChannel = easyPVA-&gt;channel(channelName);
EasyChannelPtr easyChannel = easyPVA-&gt;channel("exampleDouble");
</pre>
<p>This will attempt to connect to channel exampleDouble.
Since the client did not specify a timeout an exception wll be thrown if
@@ -109,8 +118,7 @@ returned to the client.
</p>
<p>An example of using a non cached method is:</p>
<pre>
string channelName("exampleDouble");
EasyChannelPtr easyChannel = easyPVA-&gt;createChannel(channelName);
EasyChannelPtr easyChannel = easyPVA-&gt;createChannel("exampleDouble");
</pre>
<p>This will create an EasyChannel and return it to the client.
The client must itself connect.
@@ -120,7 +128,7 @@ This is useful if the client wants to connect to multiple channels in parallel.
<h2>EasyChannel - Wrapper For Single Channel</h2>
<h3>EasyChannel</h3>
<p>This provides methods for connecting to a channel and for creating instances of
EasyField, EasyProcess, ..., EasyRPC.</p>
EasyField, EasyProcess, ..., EasyPutGet.</p>
<p>Connection must be made before any create method is called or
an exception is raised.
The following is a synchronous connection request:</p>
@@ -289,20 +297,20 @@ It has methods:</p>
<h2>EasyMultiChannel - Wrapper For Multiple Channels</h2>
<h3>EasyMultiChannel</h3>
<p>This provides methods for connecting to multiple channels.
For now clients has no reason to use this directly.
Instead they will use it via EasyMultiDouble or EasyNTMultiChannel.
A client can either use EasyMultiChannel directly or use EasyMultiDouble or EasyNTMultiChannel.
But both impose restrictions on what can be accessed.
</p>
<h3>EasyMultiDouble</h3>
<p>This provides support for gets and puts to the value field of multiple channels.
Each channel must have a value field that is a numeric scalar.
The client always sees that data as a PVDoubleArray.
The client always sees the data as a PVDoubleArray.
All channels must connect.
If any problems occur an exception is thrown.
</p>
<h3>EasyNTMultiChannel</h3>
<p>This provides support for gets and puts to the value field of multiple channels.
Each channel must have a value field.
The client always sees that data as a NTMultiChannel, which is one
The client always sees the data as a NTMultiChannel, which is one
of the types provided by normativeTypesCPP.
All channels must connect.
If any problems occur an exception is thrown.