|
Re: Check for quality information [message #1803260 is a reply to message #1803146] |
Mon, 25 February 2019 22:14 |
|
Hi,
unfortunately such a functionality does not exist. I would say currently I don't see a way to even provide such a functionality. But this comes from the data type system from IEC 61131-3, which defines that there is always valid data in a data type (maybe except for real and lreal).
I think the only option you have is that you have a dedicated Boolean value informing you about the validity of your data. You could even expand that to a time value giving you the freshness of the data. This could be rather easily be provided by an special communication layer.
To reduce the number of connections you could put this together into a struct. However structs are not so nicely usable yet in 4diac.
I hope this helps you.
Alois
|
|
|
Re: Check for quality information [message #1803264 is a reply to message #1803260] |
Mon, 25 February 2019 23:48 |
|
I just noticed that I forgot to mention the most important means IEC 61499 has to offer for you: events. A subscribe block which has never received any data, has never triggered an IND event. You can use this event to either set a Boolean (e.g., E_SR) or you trigger your FB based on the IND event. This allows you to build even more interesting applications as the means I described in my last post.
For example you can use different states in your FB for when no values have been received and when you have values. This shows much more explicit the behavior of your FB.
[Updated on: Tue, 26 February 2019 08:41] Report message to a moderator
|
|
|
Powered by
FUDForum. Page generated in 0.02054 seconds