Behringer BCR2000 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: Note Off Note On Status Byte &8n (n = channel #) &9n (n = channel #) Data Byte 1 Note # Note # Table 2.1: Data format of Note On and Note Off messages Data Byte 2 Velocity Velocity 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.