Serial Communication Problem

[Sreekumar87]

Hi,

I am facing difficulty in VISA serial communication. We have diagnostic code running in a K70P256M150SF3RM type processor. The USB 3300 transciever helps to convert the ULPI line to USB mode. We are successfully communicated with the processor through  hyperterminal (115200k baud rate). But while trying to communicate with LabVIEW we are not able to get any data from procssor. All parameters of VISA configure i have made like what i for hyperterminal.

 Please help me to resolve the issue.

Thanks & Regards,

Sree

[RavensFan]

You'll need to provide more information than that for help.  Perhaps even attach your VI.

Do you get any errors within LabVIEW?

What does the data look like that is going back and forth between the PC and the device in hyperterminal?

Are you sure you have all the settings correct?  Is it possible you are not handling termination characters correctly?

[Sreekumar87]

Hi,

Thanks alot for your response.

For dubuging purpose i used the same sample vi given in the examples. It is having a visa configure, visa open, visa write, time delay, visa read and visa close. Nothing else. In visa configure we used correct baud rate 115200 and correct termination character. Labview giving the time out error of visa read, means no able to communicate with device.

In hyper terminal it is communiacating successfully. The command going from hyper terminal is

$<command><Enter>

Response will be data or atleast it will send Invalid command from device.

In hyperterminal, there is three places for adding the command and send function for each. But device not accepting that one. We have to add directly in the command window and send, then only device accepting the command.

Thanks & regards,

Sree

[Dennis_Knutson]

But what are you sending as termination character(s) in the LabVIEW example? The basic example only sets the termination for a read. You have to manually enter what you need for a write. Use \n or \r or both like hyperterminal does.

[Sreekumar87]

I have tried End of line/Line feed string constant concatenated with command, then also the issue not solved.

[Sreekumar87]

We are connecting device with PC through USB and with the help of some driver we accessing as Virtual COM pom port from USB modem. So whether we have to use any USB type VISA functions instead of normal VISA serial functions?

[Dennis_Knutson]

No, you use the standard VISA functions though I don't understand your comment about a modem.

Please try the the \r\n in the string control.

Attach an image from hyperterminal, MAX, and the VI's front panel. You're sure you are using the Basic example?

[Sreekumar87]

Hi here attached the error, hyper terminal and MAX pictures..

[Sreekumar87]

Here atached the code and front panel..

[crossrulz]

Well, since you can't even get it to work with hyperterminal, you have some connection issues.  I'm also noticing you have some issues in your device manager.  You get those fixed first.  Then troubleshoot your connection issues.  After that, your LabVIEW code should work.  But this is NOT a LabVIEW problem.