Lon Communications Stop Working After Changes to the LON Network or IC-LON Controller

[Product_Support]

Issue

After making changes to the LON network or resetting the IC LON controller’s daughter card, communication through the IC LON controller stops. Affected IC LON objects begin displaying default values, and some third-party LON devices (e.g., those connected via LonMaker) also show default values.

Product Line

Satchwell BAS & Sigma

Environment

• Sigma IC3-Lon
• LonMaker for Windows v3.1

Cause

The SNVT bindings between the IC3-LON controller and other LON network devices have been broken. This can occur due to:

• Resetting the IC-LON daughter card
• Changes made to the LON network topology
• Third-party tools (e.g., LonMaker) modifying the network without re-synchronization
• IC3-LON controller entering an “application-less” state

Resolution

To restore communication:

1. Rebind SNVTs

   • Open the original LonMaker drawing.
   • Select Menu > LonMaker > Resynchronize.
   • Enable the following options:
     • Re-commission controllers

       

     • Use Reference Shapes

       

   • Complete the wizard to re-sync the network.

2. Upload Configuration

   • After successful re-commissioning, upload and save the NvConfig file from the IC3-LON controller to the Sigma server.

3. If Re-commissioning Fails

   • If the IC3-LON controller reports “Application-less”, the LON daughter card may require a hardware reset.
   • Refer to the article: “Sigma LON card is applicationless and cannot be reset by IC3-LON controller” for recovery steps.