Doepfer R2M Midi-Ribbon-Controller - Manual (Page 23)

R2M User's Guide V1.11 Page 23
Generating note messages only (no pitch bend)
In this mode only note messages that correspond to the position of the finger are
generated. The parameter 2-1 Midi event has to be set to Note.
If the finger moves over the position sensor without releasing the finger the result
depends upon the current setting of the parameter 4-3 Retrigger. If this parameter is
zero no new Midi note is generated as the finger glides over the manual. If the
parameter is not zero the behaviour is different: As soon as the finger reaches a
position that corresponds to another note a Midi note off message for the "old" note is
generated and the gate output turns off. After the retrigger time 4-3 that is measured
in milliseconds the new note on message is generated. Simultaneously the
corresponding CV1 is generated and the gate output turns on.
Generating single note messages with pitch bend (Trautonium mode)
In this mode pitch bend data are generated in addition to the note on as the finger
glides over the position sensor without releasing the finger. The parameter 2-1 Midi
event has to be set to Note&pitch bend relative. Touching the position sensor
generates a Midi note on message and the corresponding pitch control voltage CV1.
If the finger glides over the position sensor without releasing the finger only pitch
bend data are generated after the initial note on message. If the finger is released a
note off message is generated. To generate another note on message the position
sensor has to be touched again.
The pitch bend data depend upon the position difference between the starting point
and the current position of the finger, and the value of the 3-4 Pitch scale. Pay
attention that the pitch scale has to correspond to the setting of the pitch scale of the
receiver. The parameter 4-3 Retrigger time has no meaning in this mode.
A very important problem occurs from the Midi standard for the pitch bend message.
This message does not transmit absolute pitch information but only a relative
information. The pitch bend data reach from 0 (lowest pitch bend) via 64 (neutral) to
127 (maximum pitch bend). The full pitch bend data range 0...127 may cover
± one
semitone, ± one quint, ± one octave or any other intervall according to the setting of
the Midi receiver. Consequently the pitch scale of the R2M and the Midi receiver
have to match for a meaningful cooperation between both devices. Otherwise a pitch
change caused by note messages (i.e. absolute semitone intervals) will be not the
same as for pitch changes caused by pitch bend messages. Normally the pitch bend
range or pitch bend scale can be adjusted in the Midi receiver. For older Midi devices
it may be fixed to a certain value too. The pitch scale may be a global parameter or a
parameter that is stored separately for each preset resp. sound. Please look at the
user's guide of your Midi receiver for details how this is handled.
Fig. 8 shows three examples for different pitch scale setting at the Midi receiver. In all
cases the same pitch bend data are sent to the receiver (e.g. 0 ....127). In case a
only a small audible pitch change is caused. Case b corresponds to a medium pitch
change and setting c results in the highest pitch change – all three with the same
incoming pitch bend data !