One “RecordMeta” child element as described in Table 61 specifying the recommended polling interval may be part of the “ParameterRecordDataItem” element.
Table 61 – RecordMeta child element for Data Objects
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<RecordMeta Prefix=“opc http://opcfoundation.org/PNGSDGM/”> |
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Child element |
Property attribute of child element |
Required Content attribute of child element |
Mandatory/Optional |
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<Meta> |
opc:UpdateRate |
Recommended polling interval for the Data Object, in milliseconds. The Server may deviate from the specified update interval according to local bandwidth requirements. |
M |
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If Base Mode Parameter Access is supported, a “ParameterRecordDataItem” with “Index” attribute containing the record index to use for the BMP protocol (usually “0xB02E”) and a “RecordMeta” child element containing a “Meta” child element with “Property” attribute equal to “opc:BMPChannel” as described in Table 62 can be used to specify BMPs. The vendor specific options for the representation of BMPs in the Information Model are specified using a sequence of “RefMeta” elements (see Table 63), as shown in the GSDML sample in E.1.
The “Length” attribute of the “ParameterRecordDataItem” element is mandatory but may be ignored by Servers since the size of the memory needed varies dependent on the actual request response. Servers must follow the protocol as defined in [PDP], chapter 6.2.3 “Base Mode Parameter Access” (see GSDML sample in E.1 also). Table 63 shows the required content of the “RefMeta” child element specifying one BMP.
Table 62 – RecordMeta child element for BMPs
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<RecordMeta Prefix=“opc http://opcfoundation.org/PNGSDGM/”> |
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Child element |
Property attribute of child element |
Required Content attribute of child element |
Mandatory/Optional |
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<Meta> |
opc:BMPChannel |
Brief function description, e.g. “ControlUnit”.Remark: The parent ParameterRecordDataItem element shall specify the record number to be used for BMP Access. |
M |
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Table 63 – RefMeta child element for BMPs
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<RefMeta Prefix=“opc http://opcfoundation.org/PNGSDGM/”> |
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|
Child element |
Property attribute of child element |
Required Content attribute of child element |
Mandatory/Optional |
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<Meta> |
opc:ParameterNumber |
Parameter number (see [PDP], 6.2.3 “Base Mode Parameter Access”) identifying the parameter to be represented in the Information Model. |
M |
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<Meta> |
opc:FunctionGroupName |
Path name for the OPC UA 2:FunctionalGroupType container Object which shall be created by an OPC UA Server for the Variable representing the BMP Data Object. The path names can define a folder hierarchy using file system path syntax: <parent folder/subfolder 1/../subfolder n>. If missing, the Variable shall be created under root level as children of the GsdGenSubmoduleApplicationType Object. The RefMeta element of one BMP may contain this Meta element more than once. If so, the representing OPC UA Variable becomes a component of different container Objects. |
O |
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<Meta> |
opc:UpdateRate |
Recommended polling interval in milliseconds for the parameter. |
O |
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<Meta> |
opc:DestinationDataType |
One of the following: “Enumeration”, “ArrayFolder”, “OptionSetVariable”. “Enumeration”: Shall only be specified for “simple” BMPs with assigned text array (see [PDP], 6.2.1.4). The BMP shall be represented using a 0:Enumer ation DataType created by the Server as described in chapter 6.7.1. “ArrayFolder”: Shall only be specified for “array” BMPs with assigned text array (see [PDP], 6.2.1.4). The BMP shall be represented as “array folder” as described in chapter 6.7.1. “OptionSetVariable”: Shall only be specified for “V2” parameters with assigned text array (see [PDP], 6.2.1.4). The BMP shall be represented as 0:OptionSetType as described in chapter 7.1. |
O |
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