Notifications when a value changes - how to use them

[Sabrina_Merelli]

Hi Community,

I am trying to develop a Smart Connector which reads many values from a 3rd party software and expose them in EWS to EBO.

EBO users have the possibility to read and also write the values..

My question is if it is possible to have a notification of a value changed, written by EBO user, without having to reread all the variables at every cycle, because we have to rewrite the value to the 3rd party software.

Maybe there is some functions ready to use?

I suppose that the way to do this is using subscriptions and notifications, but since I am quite new in developing smart connectors, I'm having trouble to understand how to use them.

Someone can help me, maybe with some example?

Thanks

Best Regards

Sabrina

[mike_meirovitz]

Hi Sabrina,

What is the 3rd party software that you are connecting to? If it is an OPC server, then we have a software product called EBO-OPC Client (also an EWS Server) that is doing exactly what you need. See the attached screen capture. 

It is using subscriptions and notifications both from the EBO side and from the 3rd party OPC servers.

Please contact me with any questions.

Mike

[Sabrina_Merelli]

Hi @mike_meirovitz 

no, unfortuately it's not OPC. It is a proprietary software.

But good to see that there is already something ready for OPC, if we need it in the future.

Thanks 🙂

Sabrina

[JeffBowman]

Hi Sabrina,

To make sure that I understand.

• You have a third party system that you want to read by EBO, but also want EBO to be able to modify values within.
• You are trying to figure out how to know when EBO sets the values of one of the objects, so that you can act on that?

If the above is true, then yes, there is a sample for this. See the below link.

https://github.com/BuildingsLabs/SmartConnectorSamples/tree/master/SmartConnector.WeatherExtension/E...

Notice how the SetValues has been override, inside in this override, you can do whatever you want  (e.g.  notify the remote server of the value change).

Please let me know if you have any questions!

Best Regards,

-Jeff