Prevent data loss with Store and Forward

In industrial automation and process control, reliable data management is essential. A key strategy used to assure data integrity is store-and-forward, especially when working with historians, like OPC Expert Archive Server. A historian is a specialized database designed to collect, store, and analyze time-series data from sensors, control systems, and industrial devices. However, network interruptions or server downtime can disrupt communication between data sources and the historian, leading to data gaps.

OPC Expert’s Store-and-Forward (SAF) technology solves this problem by temporarily buffering data at the source. For example, a programmable logic controller (PLC), remote terminal unit (RTU), or data acquisition gateway can hold time-stamped values locally whenever the connection to the historian is unavailable. Once connectivity is restored, the buffered data is forwarded to the historian in the correct sequence, ensuring that no information is lost and historical records remain accurate thereby ensuring data integrity and reliability.

To achieve this fault-tolerant behavior, OPC Expert constantly buffers data locally. This ensures OPC Expert does not lose data on the network. When connectivity returns, OPC Expert sends all archived data to its destination. While OPC Expert transfers all archived historical data, OPC Expert continues sending real-time data as well. Consequently, client applications always have access to real-time (snapshot) data while historical data continues recovering.

When using SAF with SQL databases (such as Microsoft SQL, MySQL, SQLite, etc), OPC Expert sends historical data to SQL’s “History” table, and real-time data to SQL’s “Items” table. When using MQTT and SparkPlug B, OPC Expert utilizes “Retained Messages” for this capability.

OPC Expert’s local archive is circular in nature. Users can configure this buffer to take the computer’s entire disk space, or they can impose a limit (default size is 100MB). If imposing a limit, users can ask OPC Expert to overwrite old data (circular buffer keeping only the latest data). Users can also ask OPC Expert to stop archiving once the buffer is full, thereby only keeping the initial data.

OPC Expert’s Store-and-Forward (SAF) enables organizations maintain complete data histories, support compliance with regulations, and enable precise analytics. Ultimately, combining historians with store-and-forward ensures that operational data is both trustworthy and uninterrupted, even under less-than-ideal network conditions.