Hello all,

I'm trying to communicate my Laptop through its serial port with a slave device (i.e. Floboss103). The communication successfully built. when the laptop is running on battery, however, when I plug it into AC power socket (220V, 50Hz), the communication link got broken. Any idea, what can be the problem?

Thanks

 

ground loop created when the laptop takes its power from an AC source.

RS-232 signals are single ended voltages; very subject to ground loops.

 

Sounds a lot like a ground loop or difference in ground potential.

Regards
cww

 

Try an isolation transformer, sounds like a ground loop is occurring.

 

Hello ady

I'm thinking that your laptop and the serial device aren't correct wired to earth conductor ... or there's no earth network in your environment. You can solve these kind of problems with serial port isolator that allow communication with no mix the two electrical network.

Regards

Gabriele