Thales' cellular IoT products business is now part of Telit Cinterion, find out more.

You are here

ATHD*99***1# hangs | Telit Cinterion IoT Developer Community

July 30, 2015 - 3:43pm, 2434 views

I am experiencing this issue with a high percentage of MC55i we are using (hundreds):

- this issue appears only using with certain SIM cards (from different operators)

- the same SIM cards can be used successfully on identical MC55i modems

- this issue appeared only in the last few months.

1) ATHD*99***1# hangs for (let's say) 200 seconds without any answer (CONNECT/NO DIALTONE/NO CARRIER)

2) it can be interrupted by sending a single byte to the modem; the answer is NO DIALTONE. 

3) if not interrupted, after 200 seconds it gives "ERROR". After that, if AT+CEER is issued, the answer is:

+CEER: 5,19,0   (50% of *****)

+CEER: 0,0,0    (50% of *****)

The setup+connection log follows. Anyone can help? Thank you,

AT+CPIN?

+CPIN: READY

AT+CREG?

+CREG: 0,2

AT+CREG?

+CREG: 0,1

OK

AT+CSQ

+CSQ: 14,99

OK

AT^SSYNC=1;+CMGF=1

OK

AT+CMGL="ALL"

OK

AT+CGDCONT=1,"IP","internet"

OK

ATHD*99***1#

(and here it hangs for long long time)