If you don't have analyzer hardware you cannot capture GPIB transactions. The PCI-GPIB is not an analyzer but the PCI-GPIB+ is. If you look in the Windows device manager it will tell you if you have a PCI-GPIB or PCI-GPIB+.
My suggestion for trying *idn? was to see if any GPIB communication is possible before trying any device-specific configuration. Is this a 488.2 compliant instrument? If so, then *idn? should work.
Can you see the device if you do a scan for instruments in MAX? You can do this by right clicking on the GPIB interface in MAX and selecting "Scan for Instruments".
If you don't see it after doing a scan for instruments, do you have another GPIB device you could try in place of the Yokogawa?
Also, veri
fy that the GPIB address of the Yokogawa is not the same as the GPIB controller. The GPIB address of the controller is probably 0. The GPIB address of the Yokogawa should be something other than 0.