+cme error: 515


Hello, everyone!
First excuse for my bad english.
As a beginner I ´d aprreciate to learn about modem wavecom, I have here the Q2105B.
I want to use functions adl to execute AT commands. In this exemple:


I receiving the answer :

. It’s OK.
But when I execute this command:


I receiving this answer:

. It’s not ok. Why it’s happen?