Knowledge Base

This guide contains the results from validation tests of the Sofrel OPC UA Server v2.20.27 and PcVue and provides valuable tips and tricks to retrieve H_Values using Sofrel OPC UA server.

1. The validation tests of the Sofrel OPC UA server has shown excellent performance in key areas such as connection stability, reconnection handling, browsing, mapping, and read/write operations, with no loss of archived data.
   
2. During the testing, a few important remarks were noted :
   Locked : To manage the locking functionality, a dedicated variable must be used to control the locking command.
   Weekly Period Variable : The weekly period is handled as a text variable in PcVue. By default, its size is set to 132 bytes. It is necessary to increase the variable size to at least 340 bytes, matching the size required for the weekly period on the Sofrel server.
3. This section includes some valuable tips and tricks to retrieve H_Values using Sofrel OPC UA server :
   3.1. Use Subscriptions, Not Polling Groups : It simply does not work with polling. Instead, you need to use subscriptions.
   3.2. Set a Short Publishing Interval : The subscription’s publishing interval should be set shorter than the cycle change interval of the variable you’re monitoring. Ideally, it’s recommended to use a publishing interval of 0 seconds. This ensures that updates are sent immediately, minimizing the risk of missing any data changes.

   

   3.3. Disable Flow Regulation : In the advanced settings, it’s important to check the “Without flow regulation” box. Flow regulation can cause data loss by restricting the number of records to process. Disabling it ensures every data is transmitted without missing any updates, which is critical for accurately tracking changes in HValues.