USB conversion for sartorius balance

[Sniepsy]

Hi, I have a programming working for a sartorius balance communicating over RS232.  I also have an RS232 to USB converter also provided with this balance which I'd like to incorporate.  The instrument drivers presently appear to only accept RS232 devices as it checks the visa resource selected in the 'initialise' function with that of a serial object.  

How can I alter the instrument drivers by National Instruments to accomodate this USB interface?  Also how can I get the USB visa resource  to appear in the combo box on the front pannel with COM1, COM2 and LPT1?

The instrument drivers for this device are here: http://sine.ni.com/apps/utf8/niid_web_display.model_page?p_model_id=5588

Cheers

Wes

[Albert.Geven]

Because the usb port is hiding itself as a serial device, you can use this camouflage by using the serial port and you will see that the balance will respond.
Look for every comport above the ones that are present in normal rs232 connectors.

[thehobbs]

As Albert is saying, sometimes an instrument will communicate through USB as if it is a COM port for serial.  I have noticed this most with analytical instruments like balances.  You may be required to install software from the vendor to support the USB interface.  Then, it will show up as a COM port to LabVIEW.

[Sniepsy]

Ah yes I follow, so in actual fact I should keep the same program and look for an added com port in the visa IO list, right?  I'll give this a go and might just get it to work.  Thanks for your help.

Wes