Issue
In OPC-UA polling, the client actively requests data from the server at regular intervals. This actually will increase server load. The server must respond to each polling request, which can become a performance concern if there are numerous clients or high-frequency polling. Data updates may not be immediate, as they depend on the polling interval.
Resolution
This article here will describe the method of using subscription instead of the polling method. In the polling method, the OPC-UA client periodically sends requests to the OPC-UA server to fetch the data values. While in the subscription method, the OPC-UA client establishes a long-lasting subscription with the OPC-UA server. The client does not need to send periodic requests; it simply waits for the server to push the data updates. This method is event-driven, as the client receives data only when there are actual changes in the values. It reduces network traffic and processing overhead since data is only transmitted when necessary.
To use M580 OPC-UA client programming by subscription method, the attached document following here describes the steps to connect, create subscriptions and to add monitored items to the subscription.
Disclaimer
The views and opinions expressed in this article are those of the author(s) and do not necessarily reflect the official policy or position of Schneider Electric.
