B2MML schemas and definition of Equipment Classes

[Marcello Urgo <marcello.urgo@polimi.it>]

Dear all, 
I am not so experienced with xml schemas but I am dealing with
representation of industrial data using xml and I am tryong to use the
B2mml xml schemas provided by the wbf
(www.wbf.org).
In particular I want to represent data for equipment. B2MML provides the
Equipment.xsd schema:

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.wbf.org/xml/b2mml-v0400" xmlns:Extended="http://www.wbf.org/xml/b2mml-v0400-extensions" targetNamespace="http://www.wbf.org/xml/b2mml-v0400" elementFormDefault="qualified" attributeFormDefault="unqualified">

         <!-- Include the Common schema   -->

         <xsd:include schemaLocation="B2MML-v0400-Common.xsd"/>

         <!-- Import the Extension Schema         -->

         <xsd:import namespace="http://www.wbf.org/xml/b2mml-v0400-extensions" schemaLocation="B2MML-v0400-Extensions.xsd"/>

        ...

         <!-- Elements -->

        ...

         <xsd:element name="Equipment" type="EquipmentType"/>

         <xsd:element name="EquipmentClass" type="EquipmentClassType"/>

        ....

         <xsd:complexType name="EquipmentType">

                  <xsd:sequence>

                          <xsd:element name="ID" type="IdentifierType"/>

                          <xsd:element name="Description" type="DescriptionType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="EquipmentProperty" type="EquipmentPropertyType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="Equipment" type="EquipmentType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="EquipmentClassID" type="EquipmentClassIDType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="MaintenanceRequestID" type="MaintenanceRequestIDType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="MaintenanceWorkOrderID" type="MaintenanceWorkOrderIDType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="Location" type="LocationType" minOccurs="0"/>

                          ...

                  </xsd:sequence>

         </xsd:complexType>

         <xsd:complexType name="EquipmentClassType">

                  <xsd:sequence>

                          <xsd:element name="ID" type="IdentifierType"/>

                          <xsd:element name="Description" type="DescriptionType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="EquipmentClassProperty" type="EquipmentClassPropertyType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:element name="EquipmentID" type="EquipmentIDType" minOccurs="0" maxOccurs="unbounded"/>

                          <xsd:group ref="Extended:EquipmentClass" minOccurs="0"/>

                          ...

                  </xsd:sequence>

         </xsd:complexType>

Let us suppose I want to represent a Grinding Machine and to attach
some properties to it like the power and the length.
A first option could be using the EquipmentType with the
EquipmentPropertyType to add the two properties.
Hence:

<Equipment xmlns="http://www.wbf.org/xml/b2mml-v0400" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.wbf.org/xml/b2mml-v0400 B2MML-V0400-Equipment.xsd">

         <ID>GM</ID>

         <Description>Grinding Machine</Description>

         <EquipmentProperty>

                  <ID>1</ID>

                  <Description>Power</Description>

                 <Value>

                           <ValueString>Power</ValueString>

                           <DataType>int</DataType>

                           <UnitOfMeasure>Watt</UnitOfMeasure>

                 </Value>

         </EquipmentProperty>

         <EquipmentProperty>

                  <ID>2</ID>

                  <Description>Length</Description>

                 <Value>

                           <ValueString>Length</ValueString>

                           <DataType>int</DataType>

                           <UnitOfMeasure>meter</UnitOfMeasure>

                 </Value>

         </EquipmentProperty>

</Equipment>

However I am not properly satisfied of this solution, in fact, since
I have more than one grinding machine, I would like to have a default
structure for the properties of all the grinding machines.
An idea is using the EquipmentClassType:

<EquipmentClass xmlns="http://www.wbf.org/xml/b2mml-v0400" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.wbf.org/xml/b2mml-v0400 B2MML-V0400-Equipment.xsd">

         <ID>GM</ID>

         <Description>Grinding Machine</Description>

         <EquipmentClassProperty>

                  <ID>1</ID>

                  <Description>Power</Description>

                 <Value>

                           <ValueString>Power</ValueString>

                           <DataType>int</DataType>

                           <UnitOfMeasure>Watt</UnitOfMeasure>

                 </Value>

         </EquipmentClassProperty>

         <EquipmentClassProperty>

                  <ID>2</ID>

                  <Description>Length</Description>

                 <Value>

                           <ValueString>Length</ValueString>

                           <DataType>int</DataType>

                           <UnitOfMeasure>meter</UnitOfMeasure>

                 </Value>

         </EquipmentClassProperty>

</EquipmentClass>

Now I can use an xml file to organize the data for different
grinding machines:

<Equipment xmlns="http://www.wbf.org/xml/b2mml-v0400" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.wbf.org/xml/b2mml-v0400 B2MML-V0400-Equipment.xsd">

         <ID>GM1</ID>

         <Description>Grinding Machine 1</Description>

         <EquipmentClassID>GM</EquipmentClassID>

</Equipment>

My aim was to use a reference to an EquipmentClass to make available
only a set of properties.
However I experienced some problem.
 I am not allowed to put the <Equipment> and the
<EquipmentClass> in the same xml file, hence I am not able to
verify consistence of data given some specification on the different
Equipment Classes.

Is there another way to reach the same objective? As an example, could be
possible to derive a new schema from the EquipmentClassType to define an
"GrindingMachineType"?
How can I do this restricting the number and type of properties that
should be considered? It is a complexType and I was not able to use
xsd:restriction.

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://www.wbf.org/xml/b2mml-v0400" xmlns:Extended="http://www.wbf.org/xml/b2mml-v0400-extensions" targetNamespace="http://www.wbf.org/xml/b2mml-v0400" elementFormDefault="qualified" attributeFormDefault="unqualified">

                 

         <xsd:element name="GrindingMachineClass" type="GrindingMachineClassType"/>

        

         <xsd:complexType name="GrindingMachineClassType">

                  <xsd:restriction base="EquipmentClassType">

                 ...

                  </xsd:restriction>

         </xsd:complexType>

</xsd:schema>

I thank you for any suggestion.

Marcello