Alcorn Mcbride V+ series, User Manual

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16-7 Appendix B
– Alcorn McBride Serial Control Protocols
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B
MIDI Control
Advantage: Supported by most MIDI devices
Disadvantage: Not bullet-proof
Alcorn McBride Show Controllers with a MIDI IN port can also be controlled
by the MIDI Control messages SYSEX, NOTE ON, and NOTE OFF.
Start a Sequence with SYSEX “GO CUE”
The SYSEX “GO CUE” message can be used to start a sequence. Here is the
general form:
0xF0 0x7F <target address> 0x02 0x7F 0x01 <data #1> <data #2> <data #3> 0xF7
The <data #1> byte is the ASCII hundreds digit of the sequence number
(sequence index + 1). For example, if you were starting sequence #104, the
<data #1> byte is 0x31 (or “1”).
The <data #2> byte is the ASCII tens digit of the sequence number (sequence
index + 1). For example, if you were starting sequence #104, the <data #2>
byte is 0x30 (or “0”).
The <data #3> byte is the ASCII ones digit of the sequence number (sequence
index + 1). For example, if you were starting sequence #104, the <data #3>
byte is 0x34 (or “4”).
Here is an example Start Sequence #4 message sent from an Amiga (address
0xFF) to a Show Controller whose address is 0x00:
0xF0 0x7F 0x00 0x02 0x7F 0x01 0x30 0x30 0x34 0xF7
Set a State Variable
with SYSEX “SET”
The SYSEX “SET” message can be used to set the value of a State Variable.
Here is the general form:
0xF0 0x7F <target address> 0x02 0x7F 0x06 <data #1> 0x00 <data #2> <data #3> 0xF7
The <data #1> byte is the state variable index number. For example, if you
were setting variable #3, the <data #1> byte would be 0x03.
The <data #2> byte represents bits 0-6 of the desired value. For example, if the
desired value were 0x8E, <data #2> would be 0x0E.
The <data #3> byte represents the MSB (or bit 7) of the desired value. For
example, if the desired value were 0x8E, <data #3> would be 0x01.
Here is an example “Set Var #3 to 8E” message sent from an Amiga (address
0xFF) to a Show Controller whose address is 0x00:
0xF0 0x7F 0x00 0x02 0x7F 0x06 0x03 0x00 0x0E 0x01 0xF7