How can I isolate the com of the function generator from the com of the oscilloscope ?

[AbdennourTLICH]

Hi, 

I am preparing a demo on NI ELVIS III with the prototyping board by building a signal rectifier (diode bridge). The issue here is that the AC input should be totally isolated from the output. But since the function generator (my sourcr of AC input) have the same com as the oscilloscope that am using to monitor the output. So by connecting it the behavior of the circuit changes since i practically short-circuitted one of thr bridge's didodes. 

So how can i overcome this issue and monitor both the input and output with the oscilloscope ? 

Thanks and best regards, 

Abdennour

[dog-block-sock]

No.

As it said, devices have common ground.

You may buy another separate device, such as another ELVIS.