The MIDI standard provides 127 Control Change commands, called popularly “controllers”. They act  to control various functions of musical instruments. However there are not-defined commands in this group. Control Change commands with numbers from 20 to 30 belong to them . And these not-defined Control Change commands have been used to create  the MLS system.

          MLS - MIDI Light system – it is the set of Control Change commands making it possible  to steer the lighting system by MIDI- LIGHT controllers.

        Control Change commands are commands structured of two bytes:

• first is determining the number of Control Change command,

• second is determining the size of Control Change command (the level, the parameter)

       Control Change commands from 21 to 29 are making it possible in MIDI-LIGHT controllers to arrange precisely the brightness of shining in every lighting channel on one of 128 levels. The first byte of the command is determining the number of the lighting channel, and second – level of shining of the lamps.

      In the following part of  description , the bulb or a set of bulbs connected to the suitable channel of the controller is treated as the one source of  light and is called lamp.

      The CC, 21 command is steering the channel no 1, CC,22 – is steering the channel no 2, etc. till CC,28 – channel no 8. The CC,29 command is steering all channels at the same time.

      Exemplary command: CC,26,29

• CC - means Control Change,

• 26 - means the channel no 6,

• 96 - means the level of shining in the channel,

 will cause light up of the lamps in channel no 6 on the level of  75% of shinning brightness. CC,26,00 command will cause turn off the lamp. CC,29,127 command – lighting up all of the lamps to at the maximum.

         Control Change 20 command activates in MIDI-LIGHT controllers the MACRO commands or changes internal parameters of the controllers or activates its functions, which make it possible, by MIDI, for full control of it. MACRO commands act to make it possible to induce an effect of  smooth lighting up or fading lamps with the time set up earlier by one command. Change of parameters requires giving a size of particular parameter. It should be done to set this size in a controller by Control Change 30 command. To activate a function, it is enough to send one CC,20,XX command.

        Orders have a CC,20,XX or CC,30,YY form, where XX means a number of a MACRO or number of  parameter, and YY means a size of parameter from 0 to 127.

 The table below characterizes functions of each CC,20,XX commands.

* - he refers to ML-88PM, ML-84P, ML-88S, ML-80P, ML-80P2

** - he refers to the ML-640PS.

         The MIDI system distinguish 128 levels of controlling signal and the DMX system distinguish 256 levels of controlling signal. Because of that it is not possible to translate directly the value of particular MIDI commands for DMX commands. MIDI – LIGHT controllers double a level determined by MIDI command automatically and such a value is passed on as a level of DMX signal. It causes ( during direct controlling levels by MIDI ) reducing the resolution of the DMX signal to 128 levels but it doesn’t impact essentially on the working of devices because:

• inertia of the sources of light is so big that it is hard to notice a difference

•  the change of the particular parameter of the scanner or other intelligent device is occurring as a result of sending to it a level of the signal from a certain range of value. Every signal with a level of this range will cause execution of the certain determined function. The most of these devices are working in this way. The range of value for particular function is from few to tens various levels.