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BenQ M32 Series GSM/GPRS modem Help needed - no carrier

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mahesh.meena

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gprs cifsr

Hello,

We are using a BenQ M32 Series GSM/GPRS modem.
We want to connect to a Web Server and send/receive data.
To achieve this, we are using the following commands to connect:
AT
ok
AT+CGATT=1
AT+CGDCONT=1,"IP","INTERNET"
AT+CGACT=1,1
AT+CGDATA="PPP",1
ATD*99#
CONNECT
<some sequence of characters >
NO CARRIER.

However, I am getting blocked here. As per my understanding, no carrier means that something went wrong in the

authentication procedure. Unless this problem is solved, we cannot proceed further to connect and send/receive data.

Please let me know if this is the correct way to connect to any webserver and send/receive data.

Thanks,
Mahesh.
 

at+cipstatus

Try connecting using these commands.
In the example below '>>' indicates data you send to the module, while'<<' indicates data returned from the module. This example is for connecting through the AT&T/Cingular network. You'll need to get the APN, user name and password for the network you are using. Also, you'll need to add your data to the request.
Code: 
First you need to open a PDP context. 

>> AT+CGATT=1   - Attach to GPRS Service 
<< OK 

>> AT+CGDCONT=1,"IP","wap.cingular"   - Define PDP Context (cid, PDP type, APN) 
<< OK 

>> AT+CDNSCFG="208.67.222.222","208.67.220.220" - Configure Domain Name Server (primary DNS, secondary DNS) 
<< OK 

>> AT+CSTT="wap.cingular","wap(at)cingulargprs.com","cingular1" - Start Task & set APN, User ID, and password 
<< OK 

>> AT+CIICR     - Bring up wireless connection with GPRS - THIS MAY TAKE A WHILE 
<< OK 

>> AT+CIFSR      - Get Local IP address 
<< 10.190.245.172   - returns IP address assigned to your module 
<< OK 

>> AT+CIPSTATUS      - Get Connection Status 
<< OK 
<< STATE: IP STATUS   - returns status of connection, needs to be 'IP STATUS' before you can connect to a server



After you have context, you need to make a connection to the server and then send your data.
Code: 
>> AT+CIPHEAD=1      - Tells module to add an 'IP Header' to receive data 
<< OK 

>> AT+CDNSORIP=1   - Indicates whether connection request will be IP address (0), or domain name (1) 
<< OK 

>> AT+CIPSTART="TCP","www.google.com","80" - Start up TCP connection (mode, IP address/name, port) 
<< OK 
<< CONNECT OK      - Indicates you've connected to the server - IT MAKE TAKE A WHILE FOR THIS TO BE RETURNED 

>> AT+CIPSEND      - Issue Send Command 
<< >                   - wait for module to return'>' to indicate it's ready to receive data 
>> GET / HTTP/1.1   - Send data - this example is an HTTP request for the default page 
>> Host: [url]www.google.com[/url] 
>> Connection: Keep-Alive 
>> Accept: */* 
>> Accept-Language: en-us 
>>                                       - This is a blank line to indicate the end-of-header
>> CTRL_Z                           - This tells the module to send the data
<< data from server returned - Server will return data here
 
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    eyler

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Re: GPRS Help needed

Hi GSM Man
Thanks for reply,
But Benq M32 module is not supporting, Following Command
AT+CDNSCFG="",""
AT+CSTT="","",""
AT+CIICR
AT+CIFSR
AT+CIPSTATUS
AT+CIPHEAD=1
AT+CDNSORIP=1
AT+CIPSTART
AT+CIPSEND
 

GPRS Help needed

If you can post a software manual for the M32 I'll see if I can figure out the commands you need to send. BTW - I thought the M32 was no longer being manufactured.
 

Hi Gsm Man.
This problem is my problem too, I would like to make a call with G201 (Benq GPRS modem) but it show No Carrier Error to me, I attach BenQ At Command to this message. please check and have a solution for us.
thanks a lot.
 

Hi all

This problem is my problem too, I would like to make a GPRS connection with Benq M32 modem

Has anyone solved the problem
 

Hello,

This is a general explanation on how to connect to internet from a GSM/GPRS.

The AT command AT+CGDATA=1 is supposed to activate all what is needed in your GSM to
make an attachement procedure as GPRS. ( Otrherwise, do AT+CGATT=1, AT+CGACT=1, and dont forget to set the APN name with AT+CGDCONT+....)

From there, the MODULE (gsm module or gsm phone) send you some frame because he try to
negociate some parameters with you to get the connection working properly.

What you see on the reply like
CONNECT 115200
~ }#À!}!}!} }6}!}$}%Ü}"}&} } } } }'}"}(}"}#}$À#&´~

are ASCII characters who can bee converted in Hexadecimal.
All the documentation about internet frames are explained in hexa. As an example, if you convert the above frame you get

7EFF03C02101010016010405DC020600000000070208020304C02326B47E

this is an LPC frame decoded as here below:

7E : StartFlag

FF : addr
03 : controle
C021 : protocole LCP

01 : code Configure-Request
01 : identifier
0016 : Frame lenght

01 : option MRU
04 : option lenght
05 : data
DC : data

02 : option ACCM
06 : option lenght
00 : data
00 : data
00 : data
00 : data

07 : option Protocol Compression
02 : option lenght

08 : option Address and Control Field Compression
02 : option lenght

03 : option Authentication Protocol
04 : option lenght
C0 : data
23 : data

26B4 : Frame Check sequence

7E : end flag

You have to make some replay to those sentences, as well as the other coming after, in order to negociate a connection between you GSM and the Internet World, via the APN of your provider.

Usually, the connection begin with a PPP negociation, followed by a authenticate cession like PAP or CHAP, then an IPCP exchange, getting the necessary IP adresse and DNS name in order to transmit and receive IP frames on the internet.

There are very detailled explanation of the PPP, PAR CHAP IP frame that you can find on The TCP/IP Guide - The TCP/IP Guide

Philippe
 
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abbas_bh1 said:
Hi Gsm Man.
This problem is my problem too, I would like to make a call with G201 (Benq GPRS modem) but it show No Carrier Error to me, I attach BenQ At Command to this message. please check and have a solution for us.
thanks a lot.
Click to expand...

I know it is a relativley old thread

In the manual you posted (page 299)

there are special commands for TCP/IP connection

Hope that helps
 

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