Is there a way to monitor signals in existing wires? For example, with an oscilloscope and probe I can watch voltage changes. Is there a standard way to connect to an existing, working device, and monitor and record its switching over time? Such would seem to be desirable for peeking at proprietary "wake up" chirps, and to monitor device communications to establish its protocol interface.
On old phone systems, a coil device could be used to "copy" the phone signal without tapping the voltage. I guess I'm looking for something similar for general purpose wire use.
Best regards, Rick C. Hodgin