Why is NIMax displaying ~30 GPIB devices when I plug in my GPIB controller?

Hi everyone,

I have an Agilent 82357A GPIB/USB interface. That works fine and I've used it with several devices before. Now I'm trying to use it with a Keithley 236 SMU.

When I plug it into my computer, with NIMax open, and refresh the "devices and interfaces" tab on the left, not 1, but 30 devices appear, all of the form GPIB0::16::N::INSTR, where N ranges from 1 to 30. I've set the IEEE address on my SMU to 16, so that explains the 16 I think.

Here's a picture:

Curiously, I can communicate with the first one (it's the only one I tried so far) either using NIMax's VISA test panel so making a simple VI.

What's going on though, why are there 30 devices present? Should I worry?

thank you!