CR character in String control

[labview99]

The problem is that when I write a number(NS) in the principal while, the NS of the subvi dosen´t update. Maybe I have to use references,this way when I write something in the principal NS, the NS of the subvi will be updated. But I don´t know how to use it

[RavensFan]

Both things I guess at are true.

1.  Go to your \n constant.  Right click.  Do \codes display.  You'll see it now says \\n which means backslash  (it is escaped out with a backslash) and n are being sent.  It should say \n   Which means line feed character.  You should also right click, Visible Items >>  Display Style.  So now you'll see that when you are looking at \n, you know you are in \codes mode.

2.  Altenbach told you to set the NS control to "Limit to Single LIne".  But I see that setting is still not check when you right click on that control.

"the NS of the subVI will be updated".

What subVI, you have a single VI here.  This is the first you've talked about having a subVI, and none is shown in this VI. 

[labview99]

But how can I use refernces in labview? Like this when I change the value of the NS in a principal VI the value of the NS in the subvi will change

[RavensFan]

You are talking about a subVI, a "principal VI", and references.   But until now you haven't mentioned any of them.

Are you now expanding your question beyond what you originally asked?  If so, perhaps you should fill the rest of us in on what you are really trying to do and attach some code that reflects that.

Don't ask a question about serial communication, then once that is answered complain it doesn't do what you want about a handful of other things you never bothered to mention!