Hi,
Thank you for your answer.
With 'gsmctl -S -s' i was able to send multiline SMS via HyperTerminal, but my goal was to reuse my existing script for reading, extracting, deleting and responding to incoming SMS. That script uses standard AT Commands to manage SMS.
I think there is no way to send multiline SMS using 'gsmctl -A', so finally i edited the whole script to adapt it with 'gsmctl -S' commands.