ART Pro Audio TPatch - Eight Point Balanced Patch Bay - Manual (Page 9)

signal coming into the top rear jack, as shown in case C.
Finally, we can plug into both front jacks and get two
independent through signal paths where the original
source goes to a new destination and the original
destination gets a new source as shown in case D.
With the rear panel pushbutton pushed in (Normal), the
Normal mode is selected (refer to the Normal diagram
above). If you compare the two mode diagrams, you'll
notice that they're pretty similar. Only case B is different.
Now plugging a cable into the top jack breaks the
connection between the rear jacks just like plugging a
cable into the bottom jack does. Plugging a cable into
either (or both) jack(s) breaks the normalled connection.
All other aspects of the Normal mode are the same as
for the Half Normal mode.
A normalled connection is desirable for many
applications, but not all. For example, be careful not to
connect a signal processor's output and input to the
same module. Here a normalled connection would
create a feedback loop which is definitely not what you
want. Instead, use two separate modules, one for the
output and one for the input.