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TOP Server tags show wrong value after deleting and recreating a UDT

When we create a UDT in the PLC and subscribe to it in TOP Server and then delete the UDT in the PLC it still shows values in TOP Server. When we recreate the UDT it shows the wrong values for the UDT in TOP Server until we create another channel.

For example:
CHANNEL1.PLCMonitor.Status is the old channel. This is still showing a value of 0, where in the PLC it is actually a 1.
When we create another channel, called tt.vv.PLCMonitor.Status it then actually shows the correct value. This we tested on all our current versions (4.5 and 5).

We have to now reinitialize TOP Server for it to be corrected.

Online editing of PLC Program can cause wrong values

This is because you are making Runtime edits to the live processor which is a risk.  This is exactly the behavior I would expect. If you downloaded the program after making the offline edits you would not see this issue, because this would force the TOP Server to reconnect and remap the PLC names and addresses.  Re-initialize causes the Server to stop requesting information and it disconnects.  Then on the next request for information it reconnects and re-maps the PLC memory to the address names.  

For more information on how the protocols work see this link.

There are three ways to address this:

  1. Set the TOP Server device to Symbolic address under the Logix Options tab.  This will results in slower updates, but all requests will be for address names not memory location, so when the UDT is deleted we should get an error that the tag does not exist.
  2. Re-initialize the TOP Server after all on-line PLC Edits.  This will cause the Server to disconnect and reconnect to the PLC which will force it to re-index the symbolic address names and the memory locations.
  3. When doing online edits, make sure you upload the program at some point to make sure the HMI is updated.  The uploading of the program will for the TOP Server to disconnect and reconnect.  This might be the best option because re-initializing will cause all PLCs to be disconnected and creates more network traffic then just one PLC disconnect, reconnect and re-mapping.