Advantech ADAM-5510/P31 Manual page 199

• Shield connection (1)
When you want to visit somewhere, you must like to find out an
easiest way to achieve your goal, aren't you? So as electronic circuit,
all signals use the easiest way. If we connected those two cables just
with few wires, it is a difficult way for signal. So the noise will try to
find out another path for easier way for flow.