We have some remote/long distance sites with low bandwidth (<2 MBPS, and one site still uses VSAT) that need to be accessed by engineers in HQ. AFAIK, PI server in HQ can collect data from the remote DCS/PLC either by direct from PI-OPC Interface or via PI-to-PI interface installed on site. The later will require us to have PI server installed on site.
What are the pro's and con's of using either PI-OPC or PI-to-PI in this situation?
Any feedback is welcome.