NAE, SNE, SNC LON integration SNVT override - Johnson Controls - LIT-1201668 - System Integration - LonWorks Integration - 12.0

LonWorks Network Integration with Network Engines and LCS Technical Bulletin

Johnson Controls
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LonWorks Integration
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Technical Bulletin
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The Standard Network Variable Type (SNVT) Override is implemented to support LON devices that do not support updating the SNVT Table in the LON device to identify changeable SNVTs.


  • Do not confuse SNVT override with standard Override user command functions. When you use SNVT override, it ignores the SNVT table information in the LON device for that point object. It uses what is defined in the Target Reference.
  • As a general rule, the SNVT defined in the network engine (when using SNVT Override) should match the SNVT defined in the device. Failure to make a match may result in points in the network engine reading an Unreliable status or the Present Value may not display the same value as what is displayed in LNS.

When the NAE, SNE, or SNC LON Integration reads the XIF file at startup, it identifies any NVs with changeable SNVTs. This instructs the NAE, SNE, or SNC to interrogate the LON device for the SNVT table information related to the mapped point object. When the SNVT override function is used, it ignores this procedure and automatically uses the defined SNVT as identified in the Target Reference field of the mapped point object.