making phone call when the critical value is obtained

[Bugga]

can we make use of LabVIEW code for making any application in data acquision to make a telephone call when the critical value is obtained ??/

[Joe_Guo]

i don't know about the landline phones, but with standard GSM phone (T-Mobile, etc) it is fairly simple.

If you have access to network, maybe email is also an option.

-Joe

[tbob]

I suppose you could use a modem tied to the serial port and use Labview serial vi's to send commands (text) to the modem to make it dial a number. However, the receiving end would hear nothing but modem tones. Maybe a modem connected to a computer on the receiving end could be made to receive text and display it on a computer. The receiving computer would have to have a program running that is waiting to receive the text. Or maybe you could design a circuit that lights an LED or sounds a buzzer when the receiving modem's Carrier Detect goes hi.

[rolfk]

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@tbob wrote:
I suppose you could use a modem tied to the serial port and use Labview serial vi's to send commands (text) to the modem to make it dial a number. However, the receiving end would hear nothing but modem tones. Maybe a modem connected to a computer on the receiving end could be made to receive text and display it on a computer. The receiving computer would have to have a program running that is waiting to receive the text. Or maybe you could design a circuit that lights an LED or sounds a buzzer when the receiving modem's Carrier Detect goes hi.

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Well, analog modems get a rare species to find nowadays, but some of them support voice transmission. The bad news is that unlike most other commands to control modems there is not a single standard to control the voice feature of voice capable modems. Modems with modern Rockwell chips are probably the ones most available for use as voice modem. There is a post here at Developer Exchange at AT commands for a voice modem which gives you some VIs to look at to get the voice feature of a Rockwell based modem to work. It seems to work fine but I don't have a Rockwell/Connexant modem with voice capability to test it myself.

Rolf Kalbermatter

[alysko]

Well... it is a fairly simple task, if you simply need an indication of an event (without transferring any info). Have two GSM modems: one on the site and the other at your control station. As discussed in the above, on alarm conditions at the remote site, dial the number for your control station (command ATDxxx\r, where xxx is the telephone number. The other modem will detect the call, start to pulse RI (ring indicator) of serial port and send "RING" to serial port.

If you want to be sure that the call comes from the specific number, you can either set "waiting for call", or restrict the allowed incomming callers, or set the modem to tell you who is calling (using the appropriate CLI-related command on your modem, and getting a string like +CRING voice, yyyy).

The other option is to send an SMS.

If you would want to transfer some data, there are many options. The easiest ones:

* use the GPRS modem as a standard modem under windows (in linux it would be KPPP, if I am not mistaken), establish the GPRS connection and do NOT disconnect (you pay per MB-s, not per minutes). You would probably want to set the connection to automatically re-establish itself, if disconnected. This is proably the best way: a) the least hussle, b) full TCP/IP functionality in the sense that your remote PC is "permanenty" present on the Internet, and you can use DataSocket, shared variables etc..

* use modem's built-in PPP and TCP/IP stack to handle the connection. You will need to write software to control it (or use a commercial library, like www.lysko.com - > products) but become independent of the operating system and know what happens and when. The limitation here is that you have limited number (often only one) port on TCP and therefore have to handle many detals of data transfer by yourself. On the other hand, this is better than firewall since the TCP is handled by the modem, not by the operating system.

From the same link, you can also look at the real-world performance of different levels of wireless connectivity (GSM, GPRS, E-GPRS (EGPRS), EDGE, 3G and HSDPA) and economics of the subject.

[tbob]

Do you realise that you replied to a post that is over a year old?    Good reply though.