Can I connect analog probes alligator clips to different grounds? or are they all connected internally? thanks
I believe all grounds (including the one on the USB connection to PC) are common on all logic products, including the new Logic MSO. The probes are all single ended, not differential inputs. You can set each channel to a different offset voltage and âzoom inâ to a specific range, but they will all still be referenced to the same ground.
I also understand that math channels are planned (coming in a future software update), where you could subtract one single ended channel from another digitally. Otherwise, youâll need a special differential probe to see the analog difference between two voltage reference points. There are many options, so the best choice depends on specs of what you need to measure.
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Yeah, for the record, never hook up ground wires to two separate grounds. If those grounds were not previously connected, well, they are now! If those two grounds had different potentials then a current will flow between the ground pins of the MSO and youâre likely to have a bad time.
The reason oscilloscopes and logic analyzers have multiple ground wires is to try to minimize the loop distance between your measurement point and ground. If you connect a ground wire very close to where youâre measuring, you get better results. So, its good to have multiple ground wires, one per measurement point. But, theyâre all the same thing. And, yes, this applies to the scope or analyzer itself. Itâs own ground is the signal ground too. As such, one should be careful using grounded measurement devices with DUTs (device under test) that have a completely different ground level. Connecting to the DUT causes the two grounds to become one and that can lead to trouble. When in doubt, you can use a laptop that is disconnected from AC power. This makes the laptop completely âfloatingâ as far as ground reference point so the laptop can assume the same ground reference as the DUT without problem.
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