Apple Logic Pro 7.2 - Manual (Page 242)

242 Appendix
B
Logic
Control—MIDI
Implementation
Common
Control
Messages
Faders
Received: Ei,
ll,
hh Move
fader
to
position
Transmitted: Ei,
ll,
hh Fader
moved
by
user
i Fader
ID
(00
thru
07;
Master
=
08)
ll Fader
position
value
low
7
bits
(00–7F)
hh Fader
position
value
high
7
bits
(00–7F)
Example: E0,
40,
55
=
Fader
Ch.
1,
position
(55
<<
7)
+
40
Note:
Message
format
for
transmitted
fader
position
is
the
same
as
for
received
position.
Only
the
top
(high)
10
of
the
14
transmitted
bits
are
required.
Positions
0
to
1023
(decimal)
are
transmitted
as
0000
to
03FF
(Ei
00
00
to
Ei
7F
7F).
Switches
Received: None
Transmitted: 90,
ii,
ss Switch
pressed/released
by
user
ii Switch
ID
(See
“Logic
Control—Control
Surface
Layout
and
IDs”
on
page
251.)
ss Switch
State
00
=
switch
or
fader
relead
7F
=
switch
pressed
or
fader
touched
Example: 90,
0F,
7F
=
SOLO
Ch.
8
is
pressed
90,
0F,
00
=
SOLO
Ch.
8
is
released
Note:
LEDs
and
switches
use
the
same
control
message.
This
approach
means
that
an
LED
has
the
same
ID
as
its
corresponding
switch.
LEDs
Received: 90,
ii,
ss Set
LED
status
Transmitted: None
ii LED
ID
(See
“Logic
Control—Control
Surface
Layout
and
IDs”
on
page
251.)
ss LED
State
(7F
=
on,
00
=
off,
01
=
flashing)
Example: 90,
08,
7F
=
Turn
LED
08
on
90,
08,
00
=
Turn
LED
08
off
Note:
Switches
and
LEDs
use
the
same
control
message.
This
ensures
that
an
LED
always
shares
an
ID
with
its
corresponding
switch.