How to Configure Redundancy

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Ensure a reliable connection with hot-standby backup. For those systems that require an extra measure of protection, the DataHub supports hot-standby redundancy.

You can configure redundancy for two identical data sources, and if one goes down, the DataHub will automatically switch to the other. DataHub Redundancy feature allows you to configure two ‘redundant’ input data sources, which typically are read through two separate OPC servers.

If you want to, you can specify which of these data sources should be considered the primary data source if it is currently available. This will ensure the faster of the two redundant data streams is used whenever possible.

Once the redundant data sources have been configured, you simple specify the name of a single output data domain with the DataHub. This output data domain is what the client program connects to in order to read data from the DataHub. If data is available from either source domain, then the output domain (and therefore the client program) will receive live data. If the data stops arriving on the currently selected source domain, then the DataHub immediately switches over to use the other source domain. The client programs will not notice any delay and most time, depending on the update rate, no data will be lost.

DataHub Redundancy diagram

Technical Specifications:

  • Works with any data source and any mix of data sources. For instance working with two different OPC manufacturers.
  • Seamless, split-second switchovers minimize data loss.
  • Supports hot, warm, and cold standby.
  • Smart switchover only triggers when the data source changes.
  • Switchover can trigger on changes in point value or quality, for a single point or any point in a group.
  • Link monitoring quickly detects network breaks.
  • Choose between event-based monitoring of points or link monitoring of the connection, or use both together.
  • Allows the selection of a preferred data source.
  • No dependency on timers reduces switchover latencies.
  • Rate of change monitor can switch data sources when a point changes too slowly, indicating a problem.
  • Provides complete access to both data sources at all times to facilitate collecting and presenting diagnostic information.
  • Easy to use, point and click interface. No programming necessary.
  • Allows a refresh of the entire data set on switchover.
  • Use the Email/SMS feature to send notifications of switchovers.
  • Use the Data Logging feature to log switchovers and diagnostic information.