. One thing they do not implement is group execute trigger, and I've a feeling this may be a problem for me.
That is the problem with all this homebrew stuff. They are half implements and have their own low level command set as opposed to the agilent/NI low level command set. ( im talking usb driver here. The low level portion needs to exit at the GPIB32.DLL. That is the standardized command interface. Agilent , ni , ecs , keithley , rigol , they all exit at GPIB32 level. All software like VISA , labwindows , vee , testbench etc is written to hook into GPIB32.
This invariably gives problems.
Now, as for group triggers .. You can't do that over usb ... There is an appnote from NI outlining two or three things that are not possible over the usb bus due to the sequential nature of the bus.
The only true GPIB without limits can only be done through the plugin cards. They frequently pop up on ebay below 100$. Plug and play.