Behringer B-Control Fader/Rotary BCF2000 - Manual (Page 6)

6 B-CONTROL FADER BCF2000/ROTARY BCR2000 User Manual
2.4 The MIDI format
Although your B-CONTROL is very easy to use, it still makes sense to review
some information about this data format. Each MIDI command, also called
message, consists of a status byte and up to two data bytes. The status byte
defines the command type, and the data bytes contain the corresponding values.
Different types of MIDI messages used by the B-CONTROL are explained next:
Note messages:
Among keyboard hotshots, Note On and Note Off messages are among the
essential MIDI messages. Playing MIDI instruments from a master keyboard
or computer is only possible with these messages. The B-CONTROL can also
send Note Messages; however, this is not absolutely necessary to play music.
This way, note events are also used to trigger drumloops or individual notes from
a sampler. Many effects processors also allow rhythmic entering of delay times or
song tempos with note commands.
Note On and Note Off messages have the following
data format:
Status Byte Data Byte 1 Data Byte 2
Note Off &8n (n = channel #) Note # Velocity
Note On &9n (n = channel #) Note # Velocity
Table 2.1: Data format of Note On and Note Off messages
The value range for channel numbers is between 1 and 16; for data bytes it
is 0 to 127. Even though Note Off messages are not really used by keyboarders
anymore, the B-CONTROLs support sending this status information.
Velocity corresponds to the key pressure, and therefore to the volume of a
touch-sensitive keyboard (piano). Since the B-CONTROL does not feature
touch-sensitive keys, the velocity value is transmitted with a fixed value that can
be set during programming.
◊ A note command can only be assigned to keys, footswitches and push
functions of the encoder.
Control Change (CC):
Control Change Messages are some of the most “powerful” MIDI messages.
Using them, a vast number of parameters and functions can be recalled and
automated. Individual control elements (faders, rotary dials, keys etc.) can be
assigned to CC messages on your B-CONTROL. Because not only keys but also
faders and rotary dials can be used, control values can be controlled in real time
either statically or dynamically. A list with the standard controller numbers can
be found in this user manual’s appendix.
NRPN:
Additionally, controllers that have no standardized assignment can also be
used, and can therefore be assigned according to no predetermined rule.
These controllers are called NRPNs (Non-Registered Parameter Numbers).
NRPNs are further subdivided into MSB (Most Significant Byte) and LSB
(Least Significant Byte) in order to achieve a higher resolution. A lower resolution
is particularly easy to observe during fader movement of a mixer, in which 7-bit
(= 128 values) jumps in the signal level can be heard. By subdividing NRPNs
into MSB and LSB, you can achieve 14-bit resolution of faders and rotary dials,
which means that the movement of a fader is divided into more than 16,000
steps (214)! In addition to NRPNs, there are also RPNs (Registered Parameter
Numbers). RPN commands are defined as GM (general MIDI), GS (Roland) and
XG (Yamaha) MIDI standards.
Pitch Bend:
The pitch-bend wheel of a keyboard is used for tone modulation and has its own
commands in the MIDI format.
After Touch:
MIDI keyboards featuring After Touch can respond to varying key pressure even
after you release the key (i.e. after the keystroke is over) and can send this data
via MIDI. This function either reacts key-specific (key pressure) or it reacts to all
notes at the same time (channel pressure).
MIDI Machine Control (MMC):
With MIDI Machine Control, you can assign transport functions of a sequencer or
drum computer (e.g. start, stop, FFW / RWD) and locator points to individual keys
with a permanently adjustable time position (locate, punch in / out points).
Program Change Messages and MIDI Bank Select:
Program change messages are used to recall programs / presets in MIDI devices
connected to your B-CONTROL. 128 program numbers can be recalled. For devices
with more than 128 presets, use the bank select function, which lets you select a
storage bank before sending a program change.
Running Status:
Because the MIDI interface is a serial data transmission format (meaning that
its data is transmitted as a succession of individual data segments), it became
apparent very quickly that it may not be fast enough. To avoid perceptible delays
in the output of MIDI data, Running Status was designed. It suppresses the
transmission of the status byte when the same MIDI messages are transmitted
in succession. This means that, for example, during a continuous change of
the data byte of a controller (e.g. volume), the status byte is only sent once.
The only thing that is transmitted are the changes in the data byte. This goes on
until another status byte is sent. 8 bits are saved for each message sent.
SysEx Dump:
System-Exclusive data refer to a function that makes transmission of nonspecific
data via MIDI possible. This is often used for reading out memory contents and
storing them externally.
The status byte notes the data type (SysEx); the first three data bytes are a
manufacturer ID, so that when you have a large MIDI network, you can still “talk”
to the correct MIDI device.
To make using several identical B-CONTROLs at the same time possible, you can
assign a device number (device ID) in the global setup menu to each B-CONTROL,
which assures that only the correct device receives the data intended for it.
3. Control Elements and
Connections
In this chapter, we will describe various control elements of your B-CONTROL.
All controls and connectors are explained in detail, and we’ll give you useful tips
on how to use them.
(1) The 8 infinitely variable PUSH ENCODERS are used to send MIDI data.
They have two functions (turn and press) that can be assigned to different
MIDI commands.
(2) Each of these 16 KEYS can send one MIDI command.