Learn about loss of connectivity to PI Server

If the interface loses its connection to the PI Server, it logs errors and continues running normally, attempting to restore the connection to the server. While the interface is disconnected from the PI Server, it cannot read values for the snapshot placeholders (TS,VL, SS_I, etc.) and the attribute placeholders (AT.xxx), which are used to specify values for replaceable parameters in SQL queries. If buffering is enabled, queries without placeholders continue collecting data, and queries with placeholders report an error.