Always consult the official Owners Manuals first
Difference between revisions of "MIDI SysEx"
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There are 64 sysex messages, each containing 32 chunks of data. Each chunk consists of five | There are 64 sysex messages, each containing 32 chunks of data. Each chunk consists of five | ||
| − | bytes and can | + | bytes and can hold either four text characters or one 32-bit IR data sample. |
The first data message sent includes 8 chunks of text that specify the 32-character IR name, and | The first data message sent includes 8 chunks of text that specify the 32-character IR name, and | ||
| − | 24 chunks of IR data. The subsequent 63 data messages each contain 32 data | + | 24 chunks of IR data. The subsequent 63 data messages each contain 32 data samples for a |
| − | total of 2040 | + | total of 2040 samples. |
Message Format: | Message Format: | ||
| Line 85: | Line 85: | ||
lower seven bits of a byte, with the most significant bit set to 0. | lower seven bits of a byte, with the most significant bit set to 0. | ||
| − | * octet is | + | * octet is one byte containing 8 bits of data |
| − | * septet is | + | * septet is one byte containing 7 bits of data |
| − | + | byte_chunk = (data[0] & 0xFF )<< 24 | (data[1] & 0xFF )<< 16 | (data[2] & 0xFF )<< 8 (data[3] & 0xFF; | |
| − | |||
* convert four octets to five septets | * convert four octets to five septets | ||
| − | septet[0] = | + | septet[0] = byte_chunk & 0xFF; |
| − | septet[1] = | + | septet[1] = byte_chunk >> 7 & 0xFF; |
| − | septet[2] = | + | septet[2] = byte_chunk >> 14 & 0xFF; |
| − | septet[3] = | + | septet[3] = byte_chunk >> 21 & 0xFF; |
| − | septet[4] = | + | septet[4] = byte_chunk >> 28 & 0xFF; |
[[category:MIDI]] | [[category:MIDI]] | ||
Revision as of 16:25, 13 July 2011
About MIDI System Exclusive (SysEx) messages
If you're a MIDI expert, you can use SysEx messages (MIDI System Exclusive) to control the Axe-Fx II.
SysEx messages for Ultra
Ultra-specific SysEx information has been accurately acquired and organized by forum member GM Arts here.
Axe Fx II SysEx Information for loading IRs
The information below was provided by forum member LMO.
The Axe Fx II supports 2048-point impulse responses that are packaged for download in a series of 66 MIDI SysEx messages, as follows:
MIDI_START_IR_DOWNLOAD
Prepare the Axe-Fx II to receive impulse response data
Message Format:
- 0xF0 sysex start
- 0x00 manufacturing ID byte 0
- 0x01 manufacturing ID byte 1
- 0x74 manufacturing ID byte 2
- 0x03 model number
- 0x7A
- 0x20
- 0x00
- 0x10
- 0xdd checksum
- 0xF7 sysex end
MIDI_G2_IR_DATA
There are 64 sysex messages, each containing 32 chunks of data. Each chunk consists of five bytes and can hold either four text characters or one 32-bit IR data sample.
The first data message sent includes 8 chunks of text that specify the 32-character IR name, and 24 chunks of IR data. The subsequent 63 data messages each contain 32 data samples for a total of 2040 samples.
Message Format:
- 0xF0 sysex start
- 0x00 manufacturing ID byte 0
- 0x01 manufacturing ID byte 1
- 0x74 manufacturing ID byte 2
- 0x03 model number
- 0x7B function ID
- 0x20
- 0x00
- 0xdd data chunk byte 0
- 0xdd data chunk byte 1
- 0xdd data chunk byte 2
- 0xdd data chunk byte 3
- 0xdd data chunk byte 4
- --- 31 additional five byte data chunks ---
- 0xdd checksum
- 0xF7 sysex end
MIDI_CLOSE_IR_DOWNLOAD
Terminate the IR download sequence
Message Format:
- 0xF0 sysex start
- 0x00 manufacturing ID byte 0
- 0x01 manufacturing ID byte 1
- 0x74 manufacturing ID byte 2
- 0x03 model number
- 0x7C function ID
- 0xdd encoded checksum byte 0 for IR data
- 0xdd encoded checksum byte 1 for IR data
- 0xdd encoded checksum byte 2 for IR data
- 0xdd encoded checksum byte 3 for IR data
- 0xdd encoded checksum byte 4 for IR data
- 0xdd checksum
- 0xF7 sysex end
Data Chunk Encoding Scheme
The data encoding scheme translates four octets into five septets. Each septet occupies the lower seven bits of a byte, with the most significant bit set to 0.
- octet is one byte containing 8 bits of data
- septet is one byte containing 7 bits of data
byte_chunk = (data[0] & 0xFF )<< 24 | (data[1] & 0xFF )<< 16 | (data[2] & 0xFF )<< 8 (data[3] & 0xFF;
- convert four octets to five septets
septet[0] = byte_chunk & 0xFF; septet[1] = byte_chunk >> 7 & 0xFF; septet[2] = byte_chunk >> 14 & 0xFF; septet[3] = byte_chunk >> 21 & 0xFF; septet[4] = byte_chunk >> 28 & 0xFF;
