OPC-DA: Data Access
OPC-HDA: Historical Data Access
OPC-A&E: Alarms and Events

If connection issues are a problem, download our OPC Test Tool and see our OPC Connection Issues page

Note: Upcoming DCOM Security changes (KB5004442) may affect OPC client connections to remote OPC Servers. The Exele OPC Test Tool has been updated to support the required client authentication level “Packet Integrity“.

Functions include:

• OPC-DA, OPC-HDA, OPC-A&E
  Connection test (local and remote OPC Servers)
• OPC-DA
  Tag/item browsing and tag properties
  Read current tag/item values, qualities, and timestamps (Cache or Device read)
  Write tag/item values
• OPD-HDA
  Read historical tag/item values, qualities, and timestamps (raw, at time, before/after time)
  Read aggregate values (average, min, max, …)
• OPC-A&E
  Create subscriptions with filters. View and store subscription events.
  Visit our OPC A&E information and resources page