Hello, I have got an OPC UA application in which I am monitoring 20.000 tags from a Siemens S7-300 PLC via a Kepware OPC server. Once per cycle (triggered every 1 min approximately by the increment of a counter) the PLC refreshes a certain number of these 20.000 tags at the same time. Because those tags are not refreshed continuously over the 1 minute but at the same time I wanted to implement this scheme: Detect the trigger value change (counter) Create a subscription for the 20.000 tags Ask Kepware to refresh the values using on-demand flag When the on-demand flag is reset by the Kepware server it means that all the values have been read Check the notifications from the subscription to get the values that have changed Close the subscription The problem that I have is that I would like to create the subscription giving it a set of initialization values. Otherwise I will get notifications for all tags at the end of the on-demand request. The OPC foundation website stipulates that initialization set of values is something standard when creating Subscriptions but I do not find anywhere in the Labview OPC UA Toolkit how to realize this. Thank you for your help Christophe

LabVIEW

OPC UA Toolkit: how to set initialization values when creating a subscription

Hello,

I have got an OPC UA application in which I am monitoring 20.000 tags from a Siemens S7-300 PLC via a Kepware OPC server. Once per cycle (triggered every 1 min approximately by the increment of a counter) the PLC refreshes a certain number of these 20.000 tags at the same time. Because those tags are not refreshed continuously over the 1 minute but at the same time I wanted to implement this scheme:

Detect the trigger value change (counter)
Create a subscription for the 20.000 tags
Ask Kepware to refresh the values using on-demand flag
When the on-demand flag is reset by the Kepware server it means that all the values have been read
Check the notifications from the subscription to get the values that have changed
Close the subscription

The problem that I have is that I would like to create the subscription giving it a set of initialization values. Otherwise I will get notifications for all tags at the end of the on-demand request.

The OPC foundation website stipulates that initialization set of values is something standard when creating Subscriptions but I do not find anywhere in the Labview OPC UA Toolkit how to realize this.

Thank you for your help

Christophe