Event driven read plc values

[zoltyczerwony]

Hi, i'd like to ask how to approach this problem:
i have 3 vars that i would like to monitor, but i'm interested only on change of value not on value itself and as a callback i would like to read 10 other vars. Using c++ and AdsSyncAddDeviceNotificationReq i'm not able to do this - it reacts on var change but when i try to read other var i get exception. Should i be using multi threading or remove notification, read vars and add new notification?

[pbruenn]

Sounds like you are trying that in the context of your notification callback?
Yes, you have to decouple your callback from the next AdsRequest, so what I would do is let the notification callback wakeup another thread which updates the 10 other variables.