Issue
Removing or deleting a SNVT programmed within a Xenta Device that is no longer required in the application.
By removing SNVT you increase the chance of having difficulty of getting the LonMaker Template to synchronize correctly with the modified Menta file.
Understand the ramifications of deleting a SNVT and only do it when the benefits outweigh the complications.
Environment
- TAC Vista
- TAC Menta
- NL220 or Lonmaker
Cause
Removing a SNVT will upset the SNVT binding order, by causing the index numbers in the XIF file to be corrupted. In this case it is not advised to delete SNVTS
Changing a SNVT name or type will also cause indexing problems.
The Vista object name can be changed to reflect that the SNVT is spare and not used
If you have no SNVTs bound in LonMaker, the cost of deleting a SNVT is potentially having difficulty getting your LonMaker device template to synch up with the Menta file. If you have a few bindings, the downside of deleting a SNVT also includes redoing all of the bindings -- with one or two that's not a big deal. If you have 200 bindings, it can be a huge deal. Leaving a SNVT in the Menta file that isn't being used anymore just consumes one network variable input ... which can usually be dealt with easier than deleting it. So it's just weighing the pros and cons, but don't just go through without knowing what will happen.
Resolution
If the SNVT is no longer required in the Menta Application then carry out these steps.
- Disconnect the SNVT from the logic in the Menta application
- Allocate an area in you Menta application for unused SNVTs
- Move your unused SNVT into this area
- Label this area with the Text "UNUSED SNVTS DO NOT DELETE"
- Remove the public check box from the point if you do not want it visible in Vista
- Download the Menta application to the Xenta controller.
Note: If the Xenta Application is standalone (Classic) and not in a LNS database SNVTs can be deleted without a problem
