Osman,
I searched the NI Instrument Driver website (www.ni.com/idnet -- click on the "Downloads" link) and found LabVIEW drivers for several Gould oscilloscopes, but not for the 840. You may want to contact the manufacturer and see if any of their other scopes have similar (or identical) command sets to the 840. If so, then perhaps the instrument driver for another scope would actually work with your 840.
If this is not possible, you can look into developing your own instrument driver with some of the resources we have at www.ni.com/idnet.
Good luck with your application and have a pleasant weekend.
Darren N.
