Issue
The SNVT bindings break after replacing a VT6700 Viconic thermostat with a VT7600r, VR76_PIR, SE7600, etc.
Environment
- LonMaker
- NL220
- Schneider Electric SE76XX stats
Cause
The older VT7600 Viconic thermostat includes the nvoOAT SNVT. On the newer models of the Viconic stats the nvoOAT variable is no longer available. The removal of the nvoOAT variable causes the SNVT table to become unaligned and breaks the existing bindings that had been created.
Resolution
When replacing a VT7600 thermostat with any new Viconics model the existing SNVT bindings will be broken. It is important to make note of all bindings made to the stat before performing a replace with a newer stat.