MMB 2x2
MIDI Merge Box
Model 8-252 ver. 1.2
Copyri ght © 2009 CHD Elektroservis
All rights reserved. No part of this publication may be reproduced in any form without the written permis sion of CHD Elektroservis, s.r.o.
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If automatic execution of “Panic” function is allowed by “Auto-Panic” parameter, it is not
necessary to initialize the device manually. In this case initialization is carried out automatically and
MMB 2x2 returns to normal operating state after approx. two seconds.
4. DATA FILTRATION
In some cases, it is suitable to use MIDI data filtration. For example device, which does not work
with data in real time, does not have to receive such data. Or if MIDI bus is already heavily loaded, it
can be lightened by filtering data pressure sensitivity (Aftertouch), and the like.
MMB 2x2 enables to filter four types of data. These filters can be combined, in extreme cases no
filter can be turned on or all four filters can work at the same time. It is also possible to insert selected
combination of filters to MIDI inputs (to data incoming from MIDI transmitters) or to MIDI outputs (to
merged data stream) – see picture 2.
4.1. SETTING OF FILTERS
Filters can be placed on both processing way A and B independently. Setting of filters for way A
is done by sections 1 to 4 of PARAMETER [1] switch. Setting of filters for way B is done by sections 5
to 8 of PARAMETER [1] switch. Implemented filters are shown in table 2.
Table 2 – MIDI data filters selection
MIDI data DIL
Switch
Section
Data
way Data type Filtered bytes [hex]
1 A Key Aftertouch, Channel Aftertouch An dd dd, Dn dd
2 A Program Change, Bank select MSB+LSB Cn dd, Bn 00 dd, Bn 20 dd
3 A Clock, Start, Continue, Stop, Active Sensing, Reset F8, FA, FB, FC, FE, FF
4 A SysEx Messages, MTC Qtr. Frame F0 dd … dd F7, F1 dd
5 B Key Aftertouch, Channel Aftertouch An dd dd, Dn dd
6 B Program Change, Bank select MSB+LSB Cn dd, Bn 00 dd, Bn 20 dd
7 B Clock, Start, Continue, Stop, Active Sensing, Reset F8, FA, FB, FC, FE, FF
8 B SysEx Messages, MTC Qtr. Frame F0 dd … dd F7, F1 dd
Remarks:
Value “n” represents MIDI channel number, value “dd” represents databyte of a MIDI command.
Section 9 of PARAMETER [1] switch places filters to inputs or to outputs. This choice is common
for both signal ways A and B. So data filtration is enabled on both inputs or on both outputs. For
example, it is impossible to filter data on input A and on output B simultaneously.
Filters are placed on both inputs if section 9 of PARAMETER [1] switch is in lower position (ON).
If section 9 of PARAMETER [1] switch is in upper position (OFF), filters are placed on both outputs.
