I want to connect the midilogger gl800 of graphtech's company with my PC serially but it has no Labview drivers and no commands i had found from its mannuals.
That's a service manual which would be useful if you wanted to repair it. The user manual is no better. You really need to contact the vendor. They have a support forum and there are discussions on a LabVIEW driver. http://support.dataq.com/viewforum.php?f=38