Secure File transfer over External modems connected to two computers using serial cable ( Through Labview)

[Asad_Tirmizi]

Hello All.

With all due respect i am in deep trouble. Here are a set of two VI's that ive made. and i ve been banging my head since two days to get them fixed. Now what i want is to transfer a file( which initially is a text file) through two modems to another computer. Ive made a trans VI and a recieve VI. Please Find them attached. Now i give the path of the file to transfer in the trans VI and give the path in which the file should be recieved in the rec VI. Now when i connect the modems they get connected and file of the name and extension as mentioned in the rec VI is made.However it is empty and contains no data. I have tried every comprehensible alternative to solve the problem. But in vain. what i think is that when i give the path in the rec VI. it creates a file of the said name and extension at that spot. But somehow or the other my data is not able to funnel through the trans VI.

The modems get connected. The Transfer seems to be taking place, the VI of the name i store in rec is made. But in the end i get no data.

I have been trying to transfer a simple notepad file .txt, but i have to transfer atleast an audio file to satisfy the client.

Now can anyone help me spot where the problem is, i'll be very greatful.

* If some one is enthuisiastic enuff to actually try the VI on two modems then plz bear in mind that give atda command in trans modem and atd12 in the rec modem.

** Please find both the VI's attached below. To run them will require the library files which are also attached with the name of modem.

*** if it fails to work even then, Then please find attached the mother of all files containing all the sub VI's required.

Regards

[Asad_Tirmizi]

im sorry the mother of all files dint get attached. but i still think that the VI;s provided are sufficient to induce an understanding.

Have a nice day

Regards

[Dennis_Knutson]

Where did you find that old modem code? Those serial functions have not been available for several years. I would suggest you eliminate these wrappers and call VISA functions directly. Use the VISA error in/error out connections.

Do you really need something that elaborate - the byte padding and crc checking after every transmission? I would suggest you start with something simple. If you really need to use serial, start with a direct connection. Just a cross over cable between 2 pc's and a plain VISA Write.