Roland Sound Canvas Digital SC-D70 Owner's Manual page 40

Playing the Internal Sound Generator
About the "Thru function" of your software
In order for data received at MIDI IN to be passed to the sound generator section in
USB mode, the Thru function must be turned On for the software running on the
computer that is connected to the SC-D70's USB connector. If the Thru function is
turned on, data received at MIDI IN will pass through the computer and be sent to
the sound generator section, causing sound to be produced.
In MIDI mode
MIDI data that is input from MIDI IN will be passed directly to the sound generator.
fig.15-04.e
MIDI
interface
adaptor
MIDI OUT
MIDI IN
40
USB
Part group A
Part A1 - A16
GM/GS
Sound generator
Part group B
Part B1 - B16
GM/GS
Sound generator
SC-D70
For details about how to
turn on the Thru function,
refer to the owner's manual
for your software.