tests/wamp/plc.xml
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Fri, 24 Aug 2018 13:41:43 +0300
changeset 2297 96ca6b056c55
parent 2290 52afa2dec4fb
child 2298 10cfc280927c
permissions -rw-r--r--
Proper fix for error 'object has no attribute 'getSlave' in EtherCAT extension

traceback:
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 1433, in OnPouSelectedChanged
window.RefreshView()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 837, in RefreshView
self.RefreshProcessVariables()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 886, in RefreshProcessVariables
slaves = self.Controler.GetSlaves(**self.CurrentNodesFilter)
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/EthercatMaster.py", line 341, in GetSlaves
for slave in self.Config.getConfig().getSlave():
<type 'exceptions.AttributeError'>:_'lxml.etree._Element'_object_has_no_attribute_'getSlave'

Steps to reproduce problem:

- Add new EtherCAT master
- Add new EthercatNode to the master
- double click on


Revert commit "Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension"
[a3ac46366b86a0b237dac93be6b2281ac70b98a8].

The problem was that XML elements (proxy object) in some cases were created using custom XML
classes constructors and lxml.etree.Element() call and live python
patching. This causes that lxml backend doesn't know that custom python class
should be used for these XML elements.
Proxy object can be move/deleted and recreated by lxml
backend at any point in time or this can be done in python by copy/deepcopy operations.
If this happens, then newly created
proxy elements are using default class lxml.etree._Element. And all
custom functionality is lost.

All created XML elements should be always created through corresponding
parser and class lookup callback done by lxml backend.
It's described in more details in lxml documentation:
https://lxml.de/element_classes.html
<?xml version='1.0' encoding='utf-8'?>
<project xmlns:ns1="http://www.plcopen.org/xml/tc6_0201" xmlns:xhtml="http://www.w3.org/1999/xhtml" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.plcopen.org/xml/tc6_0201">
  <fileHeader companyName="Beremiz" productName="Beremiz" productVersion="1" creationDateTime="2015-02-05T11:44:55" contentDescription=" &#10;&#10;"/>
  <contentHeader name="WAMPTest" modificationDateTime="2018-08-16T16:14:30">
    <coordinateInfo>
      <fbd>
        <scaling x="0" y="0"/>
      </fbd>
      <ld>
        <scaling x="0" y="0"/>
      </ld>
      <sfc>
        <scaling x="0" y="0"/>
      </sfc>
    </coordinateInfo>
  </contentHeader>
  <types>
    <dataTypes/>
    <pous>
      <pou name="program0" pouType="program">
        <interface>
          <localVars>
            <variable name="LocalVar0">
              <type>
                <DINT/>
              </type>
              <initialValue>
                <simpleValue value="1"/>
              </initialValue>
            </variable>
          </localVars>
          <externalVars>
            <variable name="PyVar0">
              <type>
                <DINT/>
              </type>
            </variable>
            <variable name="PyVar1">
              <type>
                <DINT/>
              </type>
            </variable>
          </externalVars>
        </interface>
        <body>
          <FBD>
            <inVariable localId="1" executionOrderId="0" height="30" width="55" negated="false">
              <position x="57" y="540"/>
              <connectionPointOut>
                <relPosition x="55" y="15"/>
              </connectionPointOut>
              <expression>PyVar0</expression>
            </inVariable>
            <block localId="3" typeName="ADD" executionOrderId="0" height="60" width="67">
              <position x="168" y="525"/>
              <inputVariables>
                <variable formalParameter="IN1">
                  <connectionPointIn>
                    <relPosition x="0" y="30"/>
                    <connection refLocalId="1">
                      <position x="168" y="555"/>
                      <position x="112" y="555"/>
                    </connection>
                  </connectionPointIn>
                </variable>
                <variable formalParameter="IN2">
                  <connectionPointIn>
                    <relPosition x="0" y="50"/>
                    <connection refLocalId="4">
                      <position x="168" y="575"/>
                      <position x="151" y="575"/>
                      <position x="151" y="595"/>
                      <position x="112" y="595"/>
                    </connection>
                  </connectionPointIn>
                </variable>
              </inputVariables>
              <inOutVariables/>
              <outputVariables>
                <variable formalParameter="OUT">
                  <connectionPointOut>
                    <relPosition x="67" y="30"/>
                  </connectionPointOut>
                </variable>
              </outputVariables>
            </block>
            <inVariable localId="4" executionOrderId="0" height="30" width="73" negated="false">
              <position x="39" y="580"/>
              <connectionPointOut>
                <relPosition x="73" y="15"/>
              </connectionPointOut>
              <expression>LocalVar0</expression>
            </inVariable>
            <comment localId="5" height="478" width="646">
              <position x="23" y="10"/>
              <content>
                <xhtml:p><![CDATA[Communication between Beremiz and PLC runtime isn't bound to any specific protocol and could be extended by writing corresponding connector (see 'connectors' directory).
Beremiz reference runtime implementation supports PYRO and WAMP protocols.
This example shows how to use Web Application Messaging Protocol (WAMP).

WAMP can be used to build distributed systems out of application components which are loosely coupled and communicate in real-time. No direct connection between IDE and PLC are necessary.

WAMP is in a process to be published as official IETF standard. Draft specification is already available on IETF website.
	
To use this example you need WAMP router and standalone running Beremiz_service.
1. See README file in project's directory with detailed instructions for
setup Crossbar.io, router for open Web Application Messaging Protocol (WAMP).
2. Run crossbar
3. Create service working directory and copy wampconf.json from project_files to created directory
4. Run Beremiz_service:
./Beremiz_service.py -x 0 <working directory>
]]></xhtml:p>
              </content>
            </comment>
            <inOutVariable localId="2" executionOrderId="0" height="30" width="55" negatedOut="false" negatedIn="false">
              <position x="270" y="540"/>
              <connectionPointIn>
                <relPosition x="0" y="15"/>
                <connection refLocalId="3" formalParameter="OUT">
                  <position x="270" y="555"/>
                  <position x="235" y="555"/>
                </connection>
              </connectionPointIn>
              <connectionPointOut>
                <relPosition x="55" y="15"/>
              </connectionPointOut>
              <expression>PyVar1</expression>
            </inOutVariable>
            <outVariable localId="6" executionOrderId="0" height="30" width="55" negated="false">
              <position x="362" y="540"/>
              <connectionPointIn>
                <relPosition x="0" y="15"/>
                <connection refLocalId="2">
                  <position x="362" y="555"/>
                  <position x="325" y="555"/>
                </connection>
              </connectionPointIn>
              <expression>PyVar0</expression>
            </outVariable>
          </FBD>
        </body>
      </pou>
    </pous>
  </types>
  <instances>
    <configurations>
      <configuration name="config">
        <resource name="resource1">
          <task name="Task0" priority="0" interval="T#100ms">
            <pouInstance name="Instance0" typeName="program0"/>
          </task>
        </resource>
      </configuration>
    </configurations>
  </instances>
</project>