Because connections between a database and remote PLCs are usually unreliable, with the hub and spoke architecture, the SQL Bridge module in Ignition is installed on embedded data logging computers. This module uses the store-and-forward technique to ensure that data is never lost. The system may still be accessed through the OPC-UA stand alone architecture, or database-based tags may be used to communicate current status. By doing this, it is possible to use Tag Historian and Alarming, both of which utilize the store-and-forward system to avoid data loss. This method is ideal for historical data.