Multi-Tech Systems MTCBA-G-UF1 ユーザーズマニュアル

Chapter 3 – Troubleshooting  

Multi-Tech Systems, Inc. MultiModem® GPRS with USB User Guide 

 

 

 

 

 

Whenever I send the # commands, I receive an error. 

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You must enable the stack before the modem will accept the # commands. 

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‘AT+WOPEN=1’ will enable the stack and ‘AT#VVERSION’ will display the version of the stack. 

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If you receive an error when sending ‘AT+WOPEN=1’, then you may not have the stack present on the 
modem. 

 

How do I know if I have the stack? 

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Use the ‘AT+WOPEN=1’ command.  If it returns an error, then the stack may not be  present in the 
modem. 

 

How do I make a GPRS connection using the stack? 

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Send: AT#GPRSMODE=1 (sets the modem to GPRS mode) 

   AT#APNSERV=”APN” (sets the APN for the modem to connect) 
   AT+CGATT=1 (attaches the modem to the GPRS network) 
   AT+CGREG=1 (registers the modem onto the GPRS network) 
   AT#CONNECTIONSTART (to start the connection) 
   AT#CONNECTIONSTOP (to stop the connection) 

 

I have T-Mobile. When I try to establish a GPRS connection using the stack, the modem doesn’t connect. 
It seems like the modem gets reset. 

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Check the firmware version: ‘AT+CGMR’. 

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Version 640b had a bug that caused the modem to reset when using a non-authenticated account. 
Authenticated accounts such as AT&T and Cingular work OK.  Firmware version 641a fixes this issue. 

• 

You will have to send the modem in for a firmware upgrade. Send it to the attention of the MultiTech 
Repairs Department.  Include a letter stating the problem and that you need the version 641a firmware. 

 

How do I make a connection to my ISP using the stack? 

ƒ 

Make sure you have CSD service. 

ƒ 

Send: AT#GPRSMODE=0 (sets the modem to GSM mode) 

   AT#DIALN1=”ISP’s access #” 
   AT#DIALSELECT=1 
   AT#ISPUN=”username” 
   AT#ISPPW=”password” 
   AT#CONNECTIONSTART 
   AT#CONNECTIONSTOP 

 

I can’t use the stack to connect to the GPRS network. I keep getting CME errors. 

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Check the CME error number in the AT Command Reference Guide. 

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Make sure the modem is attached and registered with the ‘AT+CGATT?’ and ‘AT+CGREG?’ 
commands. 

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Make sure the APN is correct with ‘AT#APNSERV?’. 

 

Can I ping the modem when I have a connection established with the stack? 

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Yes, but you must be connected to an APN or server that provides public IP address and is not blocked 
by a firewall. 

 

Can I ping out using the stack? 

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Yes, but you must have the firmware version 641a or higher. 

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The command is ‘AT#PINGREMOTE=”<address to ping>”’ and ‘AT#PING’ to start the ping. 

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You must have a connection established with the stack in order to use the ping commands. 

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Does the stack support UDP? 

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Yes, but only on the firmware version 641a and above.