i want to send at command from pic to the GSM modem for establish data call .
what command i need to establish the data call over GPRS??
and if any one work in this subject ,i ask him to provide me the code for this service.
thanks alot
i want to send at command from pic to the GSM modem for establish data call .
what command i need to establish the data call over GPRS??
and if any one work in this subject ,i ask him to provide me the code for this service.
thanks alot
It is not that simple.
You need to setup the GPRS modem according to its specific AT commands. Either on a terminal or through your PIC controller.
Then you have to open a "channel" to a Static IP address since the Mobile Network ususally provides Dynamic IPs.
Because I founded a bit difficult, I preffered the solution of a ready GPRS bridge to Serial: the WirelessCOM from Teltonika (www.teltonika.com).
You only have to set up easily through a Terminal and then whenever you write even a single byte on the serial port, it establishes automatically a connection to the programmed IP and sends the data. Like Serial to serial communication.
Ioannis
thanks for replay
u have code for that service ??
and how this service work ???
i try to do some code
but the result always no carrier
no one know the at command for this service ??
I think I told you that it is totally dependant on the model of your device.
Read your device manual or data sheet and see what commands it needs.
Ioannis
Hi Ioannis,
The Telonika WirelessCom sounds ideal for an application I have in mind. I Just skimmed through the manual for it and found it a bit sketchy in parts. I assume that if you have the static IP address for your internet-connected PC then the rest is straightforward. Did you find any traps in configuring the unit?
Thanks
John
Hi John.
In general is very easy to set it up.
The only trap was the buffer, that was factory set up to a very large number, I think 2 or 4000 bytes.
So my initial attempts to send a few "hello" to the host,just seemed to fail. But the problem was that buffer did not filled up with data, so no connection was made. I had to send a few thousands of bytes to see them coming, but was not aware of that.
After changing the buffer size,all was working great. And fast really. I received my data in less than a second!
Ioannis
i find the AT command for my GSM/GPRS modem
i don't know which command to be used for establish the data call
can i connect 2 GSM/GPRS modem to send data over GPRS?
here the AT command for my GSM/GPRS modem Telit GE865-QUAD
http://www.edaboard.com/attachments/..._r5%5B1%5D-pdf
what's the code for establish this connection between the modems ??
thanx
A "data call" is not correct.
By data call I suppose you do not mean a 9600, modem connection, right? This is different story. Just get a data/fax service from your provider (usually a new data/fax number on the same SIM card) and you have it already done!
The GPRS is totally different thing. You need all the parameters from your provider (APN, username, password, type (PAP,CHAP,Auto) and maybe others).
Also you cannot establish point to point communication since the IP of the GPRS service is dynamic.So you need to establish a communication to a Static IP, usually a PC running some server software to relay data to another GPRS device.
Ioannis
iam try this command for data call on CSD
AT
OK
AT+FCLASS=0 ----->to set the data mode
OK
AT+CBST?
+CBST: 0,0,1
OK
AT+CBST= 1,0,1;------>here i changed the speed
OK
at+cbst?
+CBST: 1,0,1
OK
atd 0599592724
NO CARRIER
the result no carrier .
ok , i know it's not data call over GPRS , but i don't know how to establish data over GPRS
i can get all informations from the provider (APN,IP,etc ) ,i have spical sim cards "2 sim data cards",it's used for data call only ,every one of them have an ip address .
but what i need how to establish data call over GPRS step by step ?
thanx for your replay
According to your manual, you seem to have set it up OK for CSD.
The number you are calling does ring? Is it a land phone line with an old modem?
Does this modem answer the call?
Does this modem have the same speed or is it auto speed set?
Ioannis
Do you have a land modem to make a test?
If yes, call it and see if it rings.
Then with the help of a terminal program send ATA to the modem and see if you manage to get a connection from the GSM call.
Report results.
Ioannis
Yes that is what i meant. The good old fashioned 28.8 or 33.6 or 56K modem. Maybe you have a laptop with such a device still on.
Ioannis
i try to do this but it failed
AT+FCLASS=0 ------------->data mode
OK
at+cbst=0,0,1 ---------> set the desired modulation & speed
OK
atd 022X1X4XY ------> this # my home telephone number, me put x & y cose it's my home NO CARRIER number
i got again no carrier
What are the parameters of the at+cbst command?
Ioannis
Thar service i called DATA/FAX service (at least here I am) and is seperate service, charged according to your provider. You have to ask for activation and the provider will give you a second number for this on the same SIM card.
About GPRS, it is the best solution, speed and cost considering, but there are a lot parameters to set and all these are dependant on your device. Sorry I do not have experience with Telit.
Thats why I prefer something ready made for this purpose (see my above post #2).
Ioannis
Hi, it a relevant topic to what I am doing so I felt it would be right to have an opinion from someone on this topic. My project is to develop a tracking system. Everything is under control as far as AT commands are concerned and gprs modem is concerned (sim300 I am using).
I have to guide our software developer to develop a server which can accept the data. I am not very expert when it comes to computers, electronics is mainly my field. I do not know how to explain him and what he needs to develop. I told him the process that through gprs my modem will get internet, and will connect to your (PC) server and send the data. I will need a port number, and a static IP.
His question is that TCP/IP is different, gprs data packet is a different matter. He asks if I need socket programming which I dont have any clue about what he means.
Can you please advise me, what in terms of server, needs to be developed in order to get the data from GPRS. Please mention details as to what software if any it should be made in like C, Java, Winsock etc, what data type should the software expect and any sort of relevant info which is helpful.
The Bottom Line here is that what should be the relevant information I should give him so he can make something which can accept data from my modem through gprs connection. Just for info, my modem has built in TCP/IP stack (if that helps).
Thanks
___________________
WHY things get boring when they work just fine?
Bookmarks