What to do to build an IO Device according to Conformance Class B (certify without IRT)?

Owned by Benjamin Meyer
Last updated: 2015-05-04
2 min read
Q

What to do to build an IO Device according to Conformance Class B (certify without IRT)?

A

The Profinet Device Stack V3 supports IRT operation mode by default. (Conformance Class C) In order to pass a Conformance Class B Certification Tests the following items must be addressed.

  • Disable IRT Support in LFW using the tag list editor. (See below)
  • Remove all Conformance Class C related entries from GSDML file
  • Activate PTCP Line Delay support in GSDML: The PTCP Line Delay protocol can not be disabled. As the RT Class 3 related GSDML elements and attributes have been removed in the previous step, the PTCP Line Delay support must explicitly specified.
  • Make sure not to remove the MRP Related GSDML elements and attributes. MRP can not be disabled as well

Disabling IRT using the Tag List Editor.

In order to disable IRT support within the LFW, the firmware shall be edited using the Taglist Editor Tool provided by Hilscher. (See Tag List Editor for details). After loading the firmware into the editor, make sure that the "Profinet Features" is activated. (checkmark must be set). The property "IRT Communication accepted" must be unchecked. This is illustrated in the following image. After changing the settings, safe the modifications to the firmware and download the firmware to the netX.



Relevant Taglist settings for IRT support

Adaption of DAP within GSDML file for Conformance Class B

For a Conformance Class B only device the following modifications to the GSDML file shall be done:

  • Change "MinDeviceInterval" attribute to minimum value of at least 32 (=1ms)
  • Change "ConformanceClass" attribute value to "B"
  • Change "SupportedRT_Classes" attribute to "RT_CLASS_1"
  • Add "DelayMeasurementSupported" attribute with value "true" to "InterfaceSubmoduleItem" element
  • Remove "RT_Class3Properties" element
  • Remove "SynchronisationMode" element
  • Remove "RT_Class3TimingProperties" element
  • Make sure to not to remove the "MediaRedundancy" element

The changes are illustrated in the following GSDML DAP excerpt:

<DeviceAccessPointItem ...
                       MinDeviceInterval="32"
                       ...>
  ...
  <CertificationInfo ApplicationClass="" ConformanceClass="B" NetloadClass="III"/>
  ...
  <SystemDefinedSubmoduleList>
    <InterfaceSubmoduleItem ...
                            SupportedRT_Classes="RT_CLASS_1"
                            DelayMeasurementSupported="true"
                            ...>
<!-- To be removed:
      <RT_Class3Properties ForwardingMode="Relative" MaxBridgeDelay="5500" MaxNumberIR_FrameData="256" StartupMode="Advanced;Legacy"/>
      <SynchronisationMode MaxLocalJitter="50" SupportedRole="SyncSlave" SupportedSyncProtocols="PTCP" T_PLL_MAX="1000"/>
--!>
      <ApplicationRelations ...>
        ...
<!-- To be removed:
        <RT_Class3TimingProperties ReductionRatio="1 2 4 8 16" SendClock="8 16 32 64 128"/>
--!>
      </ApplicationRelations>
      <MediaRedundancy SupportedRole="Client"/>
       ... 
    </InterfaceSubmoduleItem>
    ...
  </SystemDefinedSubmoduleList>
  ...
</DeviceAccessPointItem>
See also...