>Do you store somewhere the already processed IDs? Without storing this info, can you explain again how can you filter (your idea) already processed records?

We rely on the LastUpdate field, which is the name given to the calculated Event.DateTime field. This is stored on the server. On the next round trip back to the client, we take everything higher than that. However, we will collect back some RO_No that we already processed, because, as you may have seen, there is no way for us to check the data locally with some kind of flag.