Hey Dirk, If I understand your question you just want to have two different GPIB controllers connected to the same GPIB bus. In this case you will just have to make sure that they have different addresses and one will be set as the controller by default and then the other one can be made the controller in your application.
Here is a KB that explains this in more detail. http://digital.ni.com/public.nsf/websearch/873BE8238AD6B0BA86256B1B004DC203?OpenDocument However, if all you want to do is to be able to access the same GPIB bus from different systems then a GPIB-ENET/100 would work great. It resides on the ethernet with an IP address. You can access this device from any computer that is connected to your network. This allows for applications to be run from different computers, but you can also use an iblock to only allow one application at a time to access the device. I hope this helps out. JoshuaP National Instruments
