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For messages containing neither Lo7 nor Hi7 placeholders, Logic Express assumes an
incoming value of 1. This is typical for pressed or released buttons. Also see “Multiply
Field” in Editing Value Parameters in Expert View.
Touch/Release Field
Enter an integer value to use the incoming MIDI message for status changes of the
destination parameter from touched to released, or vice versa. A non-zero value means
touched; a value of 0 means released. The messages are shown and edited in the same
way as the Value Change field.
Note: The Touch/Release setting only applies to the Channel Strip assignment class, and
to parameters that can be automated.
Editing Value Parameters in Expert View
The parameters in this section let you control different aspects of the values for incoming
MIDI messages.
Min and Max Fields
Enter an integer value to set the minimum and maximum range for incoming values
represented by Lo7 and Hi7. Typically, the minimum defaults to 0, and the maximum
defaults to 127. Some control surfaces (such as the CM Labs Motor Mix) may use the same
message, with different value ranges, for different controls. For more specific information,
refer to the documentation that came with your device.
Format Pop-Up Menu
Choose the encoding format for negative values in the 7-bit portions sent over MIDI. The
choices are:
• Unsigned: No negative values are possible. The full 7- or 14-bit range is treated as a
positive number. The value range is 0 to 127 (7 bit) or 0 to 16383 (14 bit).
• 2’s complement: If the most significant bit is set, the value is negative. To obtain the
absolute value, invert all bits and add 1. The value range is from –128 (7 bit) to 127 or
–8192 to 8191 (14 bit).
• 1’s complement: If the most significant bit is set, the value is negative. To set the absolute
value, invert all bits. Note that this allows two possible encoding values for zero. The
value range is –127 to 127 (7 bit) or –8191 to 8191 (14 bit).
• Sign Magnitude: If the most significant bit is set, the value is negative. To set the absolute
value, clear the most significant bit. Note that this allows two possible encoding values
for zero. This results in a value range of –127 to 127 (7 bit) or –8191 to 8191 (14 bit).
The appropriate format for a device is usually specified in its documentation. If unavailable,
check the control surface manufacturer’s website or contact them for more information.
56 Chapter 2 Customizing Controller Assignments