This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

By registering to the eWON TechForum, you agree to the HMS Privacy Policy.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.

eWON TechForum is meant to answer all questions concerning the development realized with or in an eWON device, in collaboration (or not) of Talk2M service, destined to take advantage of IIOT... This targets coding (Basic, Java, HTML, ...), viewON, APIs, Flexy oriented questions.

If you need help to set up an eWON device, establish a connection from/to an eWON, Cosy 131 related matters... please refer to your eWON distributors first as he is probably the best choice to quickly troubleshoot configuration issue.

If you are not sure, post your questions into the relevant section here under and someone will guide you so you can receive the correct answer.


  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
How to use Tag value change listener
#1
Hi everyone

I have tested Tag value change listener on page 16 of the eWON Java interface user guide(ETK1.3).
But i used ETK 1.4.
The test results are same before and after value.
Please refer to the attached file.

What is the problem?


Regard


Attached Files
.pdf   1.pdf (Size: 117,49 KB / Downloads: 9)
  Reply
#2
Timon,

This is actually normal.  The JAVA doc states :

The current value of the Tag may already have changed by the time your event
listener is called, but the value that triggered the change event is saved and the
EvtTagValueListener has specific functions to retrieve that value (and even the value
type, as it can also change).

So both functions will return different values if the value changes again during the time between the value changes the first time and when the event is fired.
Indeed, the Tag event is not an atomic event which is triggered the millisecond just after the value changes.  There can be a delay of hundred of milliseconds depending on what the eWON is doing...

Simon
  Reply


Possibly Related Threads...
Thread Author Replies Views Last Post
  Schedule action ( tag change) adrien.guillonnet 4 1.332 26-03-2018, 12:11 AM
Last Post: ziozetti

Forum Jump:


Users browsing this thread: 1 Guest(s)