how can i comunicate with USB decives that come with PC

[sriveni]

Hello,

i want to comunicate with  USB port that come with the PC.

previously i developed a program that can be comunicated with serial port, now i want the same program to comunicate with the USB ports.

thanks,

[TroyK]

VISA USB functions...

Instrument I/O >> VISA >> VISA Advanced >> Bus/Interface Specific >> VISA USB

Functions are there, the rest is up to you.

[mikeporter]

The thing is, serial and USB ports are very different things. With RS232 you send commands to the port at a very low level. I put it that way because a serial write will complete sucessfully even if there is nothing connected to the port. The USB interface on the other hand largely hides from applications the protocol used to communcate with the attached device. As a result, with a USB device you will get either some specialized driver or (more commonly) a serial port emulator that allows you talk to the device as though it were connected to a serial port.

What are the devices that you want to talk to?

Mike...

[sriveni]

hello mike,

i want to communicate with micro controller using serial port.

the micro control is programed to send the commands to a motor. all the commands from labview through the serial port.

micro control controls the motor and sends the data ( m otor positions) to the labview.

Now i had a USB to Serial Port converter. so i want try sendind the commands through USB

thanks,

[TroyK]

The USB to serial adapter should show up as a normal serial port. Just communicate to it as you normally would to a serial port.

You can ignore the fact that there is a USB interface in between (assuming the driver for your adapter is installed correctly).

Message Edited by Troy K on 06-29-2007 02:00 PM

[mikeporter]

What Troy says is correct. The only thing I could add is that you might need to check the PC's Device Manager to see where the new serial port shows up.

Mike...

[TroyK]

You could also check what port number it is assigned in MAX (Measurement and Automation Explorer).

If it doesn't show up there check the windows device manager to see if it has an error.