Hi Matthias,
Thank you very much for the report. We are in contact with ProSim. The @ and are valid values for speed and altitude descriptions, according the ARINC specification. Its also documented in our specification of this format but it looks that only is implemented in ProSim and therefore the issue.
We are working on a workaround to change the @ into a blank. Please be patience a little bit.
I keep this posting open and let you know when revision 2 is out.
Thanks again
Richard