FAQs

1.1 What is the audio output capability of the module?

1.2 Why might a call hang up when you use ATD to make a call?

2.1 How should the caller ID and Connected Line Identification Presentation (CLIP) be set up?

2.2 What should the maximum time be that a module responds with ‘OK’ after executing ATH to hang up a call?

3.1 What is the lifetime of the module’s flash memory?

4.1 Can UTF8 and UCS2 coding schemes be supported in the MMS? Which one is better?

5.1 How can a subscriber number be configured and queried?

5.2 How can a phonebook number be configured and queried?

6.1 How can PPP be used to dial up in WIN7 OS?

6.2 What are the possible reasons for PPP dial up failure?

7.1 Is it possible to convert the power supply from 5V to 4.4V using a diode?

7.2 Is it possible to supply a module with power using standard USB?

7.3 How can a module be powered using higher DC voltage (e.g. automotive 12V/24V/48V)?

7.4 How to test the power consumption in the sleep mode?

8.1 What are the design considerations when using embedded antenna?

8.2 Can the RF pin endure thunderstroke?

8.3 What is the impact if many modules work simultaneously and the antennas of the modules are very close to each other?

8.4 What is the maximum transmission speed of GPRS?

9.1 How to enable hot-swap function of SIM card?

9.2 SIM card cannot be recognized after the module works for a while

9.3 What can prevent the module from registering with the network after powering on?

10.1 What are the differences between text mode and PDU mode?

10.2 What is the maximum size of individual short messages?

10.3 What is ‘long SMS’?

10.4 Can incoming messages be received when the SMS memory space is full?

10.5 Why does the module respond with an error message when sending some SMS commands at the power-on stage?

11.1 How should UART communication failure be dealt with?

11.2 How to match the UART level between MCU and module?

12.1 What is the maximum length for TCP domain names?

12.2 What is the maximum APN length?

12.3 How many methods are there of receiving data under TCP/UDP connection?

12.4 What is the maximum length of data sent by AT+QISEND?

12.5 What is the maximum value of the parameters returned by AT+QISACK?

12.6 Why has the server not yet received the data after the module has responded “SEND OK”?

12.7 In which cases will the module respond “CLOSED”?

12.8 What is the difference between CGDCONT and QICSGP?