Reading data by induction

[TiagoRibeiro]

Hello,
anyone have any circuit or any explanation for reading data on a communication line by magnetic induction?
I would like to make a CAN data reader similar to clamp multimeter.
Thank you

 

[FvM]

The standard CAN interface uses differential signalling, a current transformer around the CAN twisted pair will ideally receive no signal. You would have to sense the (small) dipole field involved with the non-zero distance of the twisted pair wires.

Also the bus state is primarly represented by voltage not current. Signal current will be only observed between the driving node and a terminating resistor.

 

[TiagoRibeiro]

hi,
You know any circuit that does this?
Thank you.

 

[FvM]

Not a complete circuit, just a design concept.

A coil lateral to the twisted pair, an integrator circuit to reconstruct the wire current. There will be a signal inversion when the data direction changes. It has to be eliminated in the decoder hardware.