That's all, i was just trying to understand and test the commands.
I provoked the behaviour by pressing the virtual key for a long time.
Also there seems to be no possibility to limit the text length, or the text length is only partially displayed
No, there is no way to limit the length of the entered text. However, you can trap the key up interrupt and rewrite the text (ie, truncate it) to suit your application.
That's a pity, because it would have made things so nice and simple with just the command. Another option "max length" would be a great thing. Or even better the check with regex :-)
Sorry for the delayed answers, but I am 10 hours behind here in Germany.