Thanks all. Well, Melanie of course it is! I do challenge you!

By no means I asked to go through line by line. Just for reference the code was included.

The version is latest. I had from time to time problems with subroutines and the way was to shorten the length of each one. Now, the symptom is quite strange and the program execution even more. As stated earlier the third Hserout executes to the point ats0= and then it stops for about a minute! This I saw with my eyes on a terminal program. By now there is no explanation as to what might happening.

If the three commands are joined then the execution flows like calm water.

About the modem, cocacolakid, the modem has no problem to process the commands, since the CR/LF has not arrived yet.

Ioannis