Midi Machine Control MMC, Previewing | Akai MPD26 specification

MIDI MACHINE CONTROL (MMC)

MIDI MACHINE CONTROL (MMC) is commonly used to send transport control messages to hardware record or playback machines. For example, pressing [PLAY] on the MPD26 sends an MMCPLAY message to a connected multi-track recorder, which begins playing. When you press [STOP] on the MPD26, the deck also stops.

MMC COMMAND

PREVIEWING

When the [PREVIEW] button is held down, and a fader or knob is moved, the LCD displays the screen on the right. The display shows the assigned event and the last sent value of moved knob or fader. While the [PREVIEW] button is held, the fader of knob will not be transmitting any information until [PREVIEW] is released and the fader or knob is used again. At that point, the fader or knob will begin transmitting from the value selected in the New Value field while in Preview mode.

CONTROL CHANGE NUMBER

NEW VALUE

LAST VALUE	LAST VALUE
SENT	SENT

THE ADVANTAGES OF PREVIEWING

The [PREVIEW] button allows you to see what value will be sent by a controller, without actually sending the value. This gives you precise control over your parameters and helps avoid erroneous controller data being sent to your devices due to the physical position of the controller. For example, imagine that Fader 1 is being used to send three different MIDI CC numbers, depending on the preset which you are currently in. Let’s assume that Fader 1 is assigned to MIDI CC#10 in Preset 1 and MIDI CC#11 in Preset 2. While in Preset 1, you adjust Fader 1 (MIDI CC#10) to a value of 40. Now you switch over to Preset 2 and adjust Fader 1 (MIDI CC#11) to a value of 80. If you now switch back to Preset 1 and try to adjust Fader 1 (MIDI CC#10), you will notice that the transmitted values will begin at 80 (instead of 40), due to the physical location of the fader. To prevent these jumps in control values, you can hold down [PREVIEW] and move Fader 1 back to a value of 40 (which will be shown in the “Last” value readout on the display). The fader will not be transmitting information while the [PREVIEW] button is held down. Once you reset the fader back to its “Last” value, you can release the [PREVIEW] button. Adjusting Fader 1 (MIDI CC#10) will now give you a nice starting point at a value of 40.