Regular snapshot explained?
Does selecting send a regular snapshot every minute in persistent TCP window affect the transmission of live point values which update every 1/2 minute on ES poll?
No, they are independent of one another. The snapshot simply adds the current values from all the enabled points on the publisher to the publish queue on the interval specified. A regular point update will simply be added to the publish queue (if the update event is set to 'updates').
I would discourage you from using the snapshot feature with the Persistent TCP publisher, since it will mess up the amount of data in the series for a given time period (the receiver cannot identify if it was a snapshot value or a sampled value, so if you're saving real time data or all data it will save the snapshot). Then the sync will get overcounted data on the receiver and fail to sync that point in that range.
Thanks for that explanation as well I was getting duplicate entries for the snapshot.