serial modem communications

[chirs73]

I am also posting the manual for the modems that I am using. Any help is greatly appreciated.

[Raj_V]

Hi Chirs73,

My understanding is that you have your first modem going off hook, dialing the second modem's number through the emulator, which in turn, is connected to the PCB. The second modem, which is listening, detects the incoming transmission, goes off the hook, and at this point, both your modems lock up. Am I correct in my assumption? If not, feel free to let me know so we're on the same page.

It's definitely possible that your application is running too fast for your modem response. Perhaps  adding the wait between the code for your two modems should be kept in as you did in the first Modem Handshake VI provided. Also, how do you verify that the modem has begun it's handshake process before locking up? 

[chirs73]

Raj,

Here is the third revision of the program. I'm not sure how far it gets into the handshake process. Also is there a way I can contact you directly so that I can try to resolve this quicker.

Thanks

Chirs73

[chirs73]

Also when the modems lock up the second resets to a dial tone, then clicks off but the following lights on the modem remain active

Auto Answer

Carrier Detect

Transmit Ready

Off Hook

[Raj_V]

Hi Chirs73,

It might be a good idea to try to send each of these messages in your application directly from MAX using VISA Test Panels, to see if they work as expected. This way we can eliminate any issues that might occur because of the LabVIEW code and ensure that the hardware works correctly. You can open up VISA test panel by right clicking on the COM port under Serial Devices in Measurement and Automation Explorer.