Starting with version 3, Telvent DMS requires impedance attributes to be included with the export of conductor features. But impedance attributes are typically not populated on features in a GIS. Rather, they are accessed from a lookup table based on characteristics of the conductor. The configuration of impedance lookup is defined in the mapping XML.

The default Minerville mapping XML uses the MMENG_CONDUCTOR_ELEC table from the ArcFM sample engineering analysis tables for impedance lookup. This default lookup is not valid for feeder exports in a production environment, because MMENG_CONDUCTOR_ELEC is intended for secondary circuit analysis. So the default lookup configuration should be regarded as a sample only.

The following mapping XML snippet enables lookup for the impedance property “r” (resistance) for underground conductor features:

<cimProperty name="cim:ACLineSegment.r">
 <Lookup tableName="MMENG_CONDUCTOR_ELEC" keyField="UNDERGROUND,MATERIAL,CONDSIZE,INSULATION" valueField="R_PER1000_UNITS_LENGTH" optional="true">
  <constant value="1"/>
  <sourceField name="ConductorInfo.CONDUCTORMATERIAL" useDomain="false" useAny="true"/>
  <FixCondSize>
   <sourceField name="ConductorInfo.CONDUCTORSIZE" useDomain="false" useAny="true"/>
  </FixCondSize>
  <sourceField name="ConductorInfo.INSULATIONTYPE" useAny="true"/>
 </Lookup>
</cimProperty>

The lookup table is identified as MMENG_CONDUCTOR_ELEC. The key fields in the lookup table are UNDERGROUND, MATERIAL, CONDSIZE, and INSULATION. These keys are matched with the constant 1 and the fields CONDUCTORMATERIAL, CONDUCTORSIZE, and INSULATIONTYPE in the GIS feature to obtain a lookup. The output of the lookup is a resistance value from the R_PER1000_UNITS_LENGTH field in the lookup table. This value is applied to the “r” property in CIM.