Ok, we have a standard Agilent oscilloscope and need to get a V-I curve for this bad boy. We got a BNC cable with our V and another with our I, but we can't get a V-I curve at all. We just get 2 flat lines that correspond to V and I independantly. Our instructions say we just plug V into the X end of the 'scope and the I into the Y. Is there a menu somewhere to set this thing or what?