I am using the above set up as Standard PCMCIA Card Modem as I need to develop an application using standard AT+ commands.
To send an SMS I use:-
wait for OK
wait for >
The Message text <CTRL-Z>
If I do this command sequence from a terminal emulator then it works fine and I get the correct response.
The same thing happens when I try the sequence (from C#) in step through mode, where there is a debugger pause between the GMGS command and the sending of the text.
But if I try to run this outside the debugger I get +CMS ERROR 310
which apparently means no SIM in the phone and makes no sense at all. If I now stick a breakpoint between the last two statements then again the message is sent and all is well.
I have tried putting a Sleep(x) pause between the last two statements with values varying between 10 and 1000 ms. to no avail.