Hello again, sorry that I had lot of problem.

This is another problem that I get from my customer. He said that the modem couldn’t send sms and make a dial. The error report said is +CMS ERROR: 512. And my knowledge about that error is in the GSM TS 04.08 specifies that if an incoming SMS arrives when trying to send an SMS, the outgoing SMS could be rejected. And I’m not waiting for any message that arrives or incoming call at all.
This my modem setting

651_09gg.Q2406B 1478872 070705 14:15

+CSQ: 26,99

Q:0 V:1 S0:000 S2:043 S3:013 S4:010 S5:008

+CR:0 +CRC:0 +CMEE:1 +CBST:0,0,1

+SPEAKER:0 +ECHO:0,1 &C:1 &D:2 %C:0

+IPR:115200 +ICF:3,4 +IFC:2,2


Thank you for any replies.

Don’t know if it would help you anything but I would recommend using 651a instead of 651, if possible.

I think CMS ERROR: 512 can occur when signal is weak too.

As i can see in your modem settings description, CSQ values are 26,99, which mean the BER is 99… this is probably the problem…

No, it doesn’t.

Valid values for BER are 0-7;
99 indicates “not known or not detectable”.

Thanks all. I have resolved the problem.
The idea is from tobias, but I’m not change the firmware, I just re flash the firmware. And it is work again.