1、 F1003 can’t send SMS.

--Please check if AT command is workable, and signal is good enough, then check if SIM card is fastened well.

--You have run out of charge of SIM card?

--Baud rate is correct, and the SMS Center No. is correct?

--The RS232 cable is ok ?(2,3 cross and 5 straight)

2、 I can send SMS with F1003, but receiving SMS is unavailable, why?

--Please check if the storage of SMS is full.

3、 I can receive SMS with F1003, but sending SMS is unavailable, why?

--Normally, it is the problem of wrong SMS Center No., and you can check the current SMS Center No. with AT Command: AT+CSCA?

4、 When I use F1103 for dial-up, it shows hardware conflict.

--Please check if the COM port is occupied by other devices, baudrate is correct? or AT command is ok?

--Flow control shall be “none”

--AT+CGDCONT=1,”IP”,”CMNET” shall be correctly filled when dial-up (CMNET is the APN of China Mobile, please fill your local APN)

--You can use our dial-up software.

5、 F1103 show error code “777”, “743” when dial-up

--You have run out of the charge of SIM card?  The signal is good enough?

--You may reboot your PC or test it with another PC.

--You can use our dial-up software.

6、 There have data loss when use F2003 for sending messages to cell phone

--Use another serial tool for testing.

--Check if the baud rate and parity bit of serial tool is the same as F2003.

--Check if sending format is accordance with display format.

7、 How many bytes for each message of F1003?

--140 bytes, special code is included.

8、  How to send SMS under AT TEXT mode?

--Sets the modem into text mode via AT+CMGF=1, and you can get more code info via AT+CSDH=1.

--Check if the SMS Center(SMSC) is correct via AT+CSCA?

--Use following commands

AT+CMGS=“Cell Phone No.”

>imput the message, end with CTRL Z

+CMGS: XX

OK