Specifications

Appendix B Logic Control—MIDI Implementation 179
Metering
Received:
D0, XX Peak level
<Hdr>, 20, ii, mm, F7 Channel meter mode
<Hdr>, 21, yy, F7 Global LCD meter mode
Transmitted: None
XX Meter level in the form of ( 0 h h h l l l l ):
hh Channel to be addressed (0 thru 7)
ll Meter level:
0 thru C = level meter 0% to 100%
Overload not cleared!
E = set overload
F = clear overload
ii Channel ID (0 to 7)
mm mode bit map in the form of ( 0 0 0 0 0 l p s ):
l Enable level meter on LCD
p Enable peak hold display (horizontal only)
s Enable Signal LED
yy 00 = horizontal; 01 = vertical
Notes:
• There is only one level meter per channel. For stereo tracks, use the maximum of left
and right levels.
• Only transmit peak levels. Logic Control automatically decreases the level meter bars,
and switches off the Signal Present LED with time. This way, MIDI bandwidth takes up
only a fraction compared to implementations where the current level (and peak
level) has to be transmitted constantly.
• Decay rate is approximately 300ms per meter division (1.8 seconds to fall from 100%
to 0%)
• The LCD meter value and the duration of the Signal Present LED are controlled by the
same data byte.
• While the LCD switches between horizontal and vertical metering mode, it ignores
LCD messages. After you sent an LCD metering mode change message, you should
delay LCD messages for at least 600 ms.