topic Re: Communicate a PC with GPRS module through TCP/IP in LabVIEW

Communicate a PC with GPRS module through TCP/IP

Pnt — Tue, 08 Jan 2008 11:26:22 GMT

I want to exchange data between a PC and a GPRS module.

One problem i have is that my PC is on a local network and the IP my computer has, is the local IP. The server has a different IP through we connect to the internet. Which IP I must use and how?

I know almost nothing about TCP/IP (i have use the Labview TCP/IP functions successfully at our local network) and i would like to ask for informations. I know it is a little irrelevant with Labview, but as there are many users who uses GPRS modules, i would like informations about how to connect a GPRS module through TCP/IP. Simple examples will be the best.

Any informations, links, recommended books, will be highly appreciated.

Thanks

Re: Communicate a PC with GPRS module through TCP/IP

Pnt — Wed, 09 Jan 2008 06:11:35 GMT

Someone ?!

Re: Communicate a PC with GPRS module through TCP/IP

rolfk — Wed, 09 Jan 2008 13:50:18 GMT

@Pnt wrote:
I want to exchange data between a PC and a GPRS module.
One problem i have is that my PC is on a local network and the IP my computer has, is the local IP. The server has a different IP through we connect to the internet. Which IP I must use and how?

I know almost nothing about TCP/IP (i have use the Labview TCP/IP functions successfully at our local network) and i would like to ask for informations. I know it is a little irrelevant with Labview, but as there are many users who uses GPRS modules, i would like informations about how to connect a GPRS module through TCP/IP. Simple examples will be the best.

Any informations, links, recommended books, will be highly appreciated.

Thanks

It's not fully clear to me what you want to do but I assume that you want to use a GPRS modem to connect your computer to internet. This is entirely independant of LabVIEW. First you need to install a modem in your system and configure it to communicate with the GPRS modem. It's mostly like installing any other modem in your system and if you use Windows using the Modem Wizard that can be accessed from the Phone and Modem Options Control Panel or similar depending on your Windows version is probably a good start. You will want to install a Standard 19200 or 38400 modem in most cases.

Then you need to configure that modem and here you usually need to add an Extra Initialisation command which will depend on your modem type and most likely on your GPRS provider too.

Next step is to configure a dialup connection using that modem. In Windows XP you do that from the Properties window for the My Network Places window. Other Windows versions might have that as a Control Panel application or somewhere else. Create a new connection is the part you want there and selet the previously installed modem. The dialup number is highly Network Provider specific and you will have to get that from them somehow, though it can proof a real challange to get a support person that even understands what you want to do and then is able to locate the according knowledgebase article in their database.

One you have a network connection setup like that and can connect to the network provider from Windows directly you can also use LabVIEW TCP/IP functions to connect to any TCP/IP endpoint that would be reachable over that connection.

Rolf Kalbermatter

Re: Communicate a PC with GPRS module through TCP/IP

Pnt — Wed, 09 Jan 2008 14:36:08 GMT

Thanks for answering Rolf.

To be more clear : i have a GSM/GPRS module (like the well known Wavecom's modules (or Falcom, Telit...)). They accept AT commands and they have a D-sub-9 serial connector. They connect to serial port of the PC. I want to connect to the internet with TCP/IP (by sending AT commands). But i can not find any manual..! The module have some commands for TCP/IP but no explanation or examples. Those modems have no drivers, they accept only AT commands.

For example i have to set APN and IP Address which i don't understant what i should write to. It is independant of Labview but i do not know where to look for information.

If someone knows anything similar please reply.

Re: Communicate a PC with GPRS module through TCP/IP

Wiebe@CARYA — Wed, 09 Jan 2008 14:40:03 GMT

Hi Pnt,

I don't know if I can answer all your questions, but perhaps a few...

To use TCP/IP in LabVIEW, you can use the standard TCP functions (in
communications>protocols, or something). LabVIEW uses the default network
connection, and I have no idea how to choose if you have more then one.

To establish the connecion, we used a combination of the serial port (which
is the interface to the GPRS module), and a program called rasdial.

We configure a new network connection in windows, just like you would with
any other connection. The supplier of the GPRS module send us instructions
about phone numbers etc. needed to do this configuration. If you've done
this correctly, you can test your new connection simply by opening a web
page (like www.carya.nl, shaless plug). Do remove all other connections!

We use rasdial to start and stop the connection with the command line from
LabVIEW. You should also be able to have the connection start when Windows
starts up, but we needed more control.

Before we start the connection with rasdial, we enter a pin code through the
serial port. This can be done with AT commands. I think you can configure
the windows network setup to automatically do this as well, but your pin
code will be readably by anyone that can open the configuration utility...

Hope it helps,

Wiebe.

Re: Communicate a PC with GPRS module through TCP/IP

rolfk — Wed, 09 Jan 2008 17:06:02 GMT

@Pnt wrote:

Thanks for answering Rolf.

To be more clear : i have a GSM/GPRS module (like the well known Wavecom's modules (or Falcom, Telit...)). They accept AT commands and they have a D-sub-9 serial connector. They connect to serial port of the PC. I want to connect to the internet with TCP/IP (by sending AT commands). But i can not find any manual..! The module have some commands for TCP/IP but no explanation or examples. Those modems have no drivers, they accept only AT commands.

For example i have to set APN and IP Address which i don't understant what i should write to. It is independant of Labview but i do not know where to look for information.

If someone knows anything similar please reply.

In that case what I wrote applies fully to you. You do not want to communicate with the modem from LabVIEW itself. You want to use TCP/IP and that means using the Windows socket library that the LabVIEW TCP/IP functions access. The modem then needs to be installed in the Windows system as a dialup adapter. There is really no other way to use a modem, GPRS or not, as TCP/IP communication path. Trying to implement TCP/IP,SLIP/PPP and all that in LabVIEW would be a many man year project with lots of problems and the likely chance that it will never fully work.

So get your modem to work under Windows so that you can use your browser to view some internet pages and once that works you can also use the LabVIEW TCP/IP functions to communicate with whatever is there.

Direct communication to the modem through AT commands would only make sense if you wanted to access the SMS facilities in that modem instead. Even that is not exactly trivial as I can attest to, especially if you want to make it work with more than one GSM modem type.

Your modem manufacturer should be able to give you the necessary modem initialisation string to put your modem into the right GPRS mode and your mobile phone network provider should be able to tell you the dialing number to fill in the dialup configuration. No need to do anything else!

As Wiebe explained rasdial.exe would then make it possible to connect to the internet under LabVIEW control.

All in all it's doable but I have spent many hours to get it working last time I did. A few of those were spent waiting on the line for the support persons of the mobile network provider to answer my calls and then playing the ping pong game to get a person that actually knows what a computer is and that it's actually possible to connect a modem to it to use their services.

Rolf Kalbermatter

Message Edited by rolfk on 01-09-2008 06:06 PM

Re: Communicate a PC with GPRS module through TCP/IP

Pnt — Thu, 10 Jan 2008 13:54:29 GMT

Thank you Rolf & Wiebe.

If someone knows something more... please post...

Re: Communicate a PC with GPRS module through TCP/IP

rolfk — Thu, 10 Jan 2008 16:56:13 GMT

@Pnt wrote:
Thank you Rolf & Wiebe.

If someone knows something more... please post...

I don't want to sound bold, but there is not much more to it. The challange will be to setup the modem right in your version of Windows, which is a typical Windows problem although one that less and less people get to deal with nowadays and to get your network provider to give you the correct information to be able to connect to their network. All in all things that we here can help even less with than more dedicated forums such as Windows support or your network providers support line. Here in the Netherlands the dialup string to be configured is different for each mobile network provider. Also there are variations depending on the modem type.

Rolf Kalbermatter

Re: Communicate a PC with GPRS module through TCP/IP

Pnt — Thu, 10 Jan 2008 17:15:10 GMT

Rolf, i haven't find the time to look into details to those you wrote, but i think their is more..

My problem as i said, is that i must use AT commands (for many reasons) to have two modems to communicate. Windows and Labview stuff are only secondary.

As i wrote:

"One problem i have is that my PC is on a local network and the IP my computer has, is the local IP. The server has a different IP through we connect to the internet. Which IP I must use and how?"

"For example i have to set APN and IP Address which i don't understand what i should write to"

Also

which IP i must use to establishe a communication between two modems without any PC?

Irrelevant with Labview...thats why i asked , if someone knows a more propriety forum...

I have spend many-many hours searching...................

Rolf said

"and you will have to get that from them somehow, though it can proof a real challange to get a support person that even understands what you want to do and then is able to locate the according knowledgebase article in their database."

How true... providers have not help at all...

Re: Communicate a PC with GPRS module through TCP/IP

craigc — Thu, 10 Jan 2008 17:46:15 GMT

Just Geussing, but it sounds like you need to know which IP's are available from the server or if it runs DHCP. Then program a suitable IP address into the device in a simalar fashion to setting a static IP on a pc. Then the module may be able to start TCPIP command from the server and eventually your pc. There may be a way to communicate directly to the pc without going through the server, however i am unsure about that. Think its called a bridge or something???

Trying to be helpfull but im clutching at straws here 🙂

Craig

Re: Communicate a PC with GPRS module through TCP/IP

rolfk — Thu, 10 Jan 2008 18:21:39 GMT

@Pnt wrote:
Rolf, i haven't find the time to look into details to those you wrote, but i think their is more..

My problem as i said, is that i must use AT commands (for many reasons) to have two modems to communicate. Windows and Labview stuff are only secondary.

As i wrote:

"One problem i have is that my PC is on a local network and the IP my computer has, is the local IP. The server has a different IP through we connect to the internet. Which IP I must use and how?"

"For example i have to set APN and IP Address which i don't understand what i should write to"

Also

which IP i must use to establishe a communication between two modems without any PC?

Irrelevant with Labview...thats why i asked , if someone knows a more propriety forum...

I have spend many-many hours searching...................

Rolf said

"and you will have to get that from them somehow, though it can proof a real challange to get a support person that even understands what you want to do and then is able to locate the according knowledgebase article in their database."

How true... providers have not help at all...

Believe me for IP communication over a GPRS modem you do NOT want to program the modems on the AT command level yourself. Unless you have a very deep TCP/IP protocol understanding together with many many man months of professional development time of the level of system programmer. I do know as I studied the TCP/IP protocol to some extend.

Windows (and every other modern OS) already can do that so don't try to invent the wheel especially when it is such a complicated wheel as this one.

Or maybe you want to do a point to point connection between two computers. If you insist on using TCP/IP, a direct GPRS modem connection is not feasable. A GPRS modem is not meant to operate as a server interface, for that you need quite different network termination hardware, that is typically present in the GPRS switch stations of mobile network providers. Those interfaces cost a lot more than a single modem and require a whole set of extra infrastructure to operate the way they do. Your two GPRS modem will have to connect to a network service provider somehow. They can't talk directly to each other. For that to work you would need WiFi or other similar wireless network gateways that can operate in client to client communication directly.

Rolf Kalbermatter

Message Edited by rolfk on 01-10-2008 07:21 PM

Re: Communicate a PC with GPRS module through TCP/IP

Salac — Tue, 29 Jul 2008 13:42:02 GMT

Dear Rolfk,

I have central location with GPRS modem and PC. At remote locations there are GPRS routers transparent to Modbus and Modbus device. For GPRS I have coorporate APN.

I make dial-up connection from PC to GPRS modem and I can ping remote locations. I want to make LabVIEW application to read data from remote locations. So, I have to encapsulate Modbus into TCP/IP. How to do that? I can't open TCP Connection. What's the port number for LabVIEW function TCP Open Connection?

Re: Communicate a PC with GPRS module through TCP/IP

Benkelys — Thu, 13 Feb 2020 04:21:45 GMT

I think I know exactly what you need. You want to create a TCP server with LabView where you open a port on a PC that is connected to an internet network. You have to configure a port redirection that points to the local computer that has the TCP server. on the other hand, use the modem to connect it to the public IP of the modem where the server is to make a direct bridge to the GPRS modem to later control some device such as a PLC or some machine that uses the communication protocol as Modbus or equivalent when connected to the serial port of the modem. either by RS485 or RS232

Re: Communicate a PC with GPRS module through TCP/IP

rolfk — Thu, 13 Feb 2020 07:30:10 GMT

You resurrected a 12 year old thread! And didn’t add significant information. From his last message it appears that he had the TCP/IP connectivity through his WAN working (or maybe through GPRS, the explanation isn’t crystal clear which added to the difficulties). At least he could ping his remote system.

There seems to have been (past tense after 12 year is quite possible) a Modbus system on the remote side. It’s not.fully clear if this was Modbus TCP but if it would be, I couldn’t understand where the problem was.
If it was serial Modbus you need to have a serial port remote access solution. The easiest solution by far would be a serial to TCP converter from Moxa or similar. If there is a possibility to install software on the remote side you could also install NI-VISA on there and enable NI-VISA server and access that port from another computer over the network through NI-VISA.

GPRS as a solution is pretty much obsolete nowadays and in this specific situation I never fully understood why he thought he would need to program it directly through AT commands.