LUSP Data Class ID Message (03 hex)
This message is transmitted from the system in response to a request for the Data Class ID at a specific Control Address. This allows external equipment to build a control tree of the system: request the Data Class ID (this message) at an address, check it's description to see if it is a control "branch" or a "leaf". If the address contains a "branch" flag, you know you can go one level deeper until hitting a "leaf".

Transmit only
Byte # Value HEX  Description Notes 
1 F0 Sysex ID (Start) 
2 06 Lexicon ID 
3 0bbb bbbb Product 
4 0bbb bbbb Device ID  0-127
5 03 Message type  Data Class ID
6-9 0n Class ID(2 bytes)  The max value here will be the one less than the "Number of  Class IDs" field of the "System Configuration" message 
-- 0n  Number of control levels (2 bytes)  (optional)This field defines how many control levels are used in the  address. This is a 16 bit field so the address can have up to 64k digits (control levels) 
-- 0n  Control level 0 (A) (address) (2 bytes)  (optional)This is the first control level. It defines the level 0 (A) control address of the "Data Type". The control level addresses are 16 bit fields so the control addresses can be 64k deep. Note that letters are used to help differentiate between levels and their values. 
-- 0n  Control level 1 (B) (address) (2 bytes)  same as previous 
-- 0n  Control level 2 (C) (address) (2 bytes)  same as previous 
-- 0n --- up to Control level 65535  same as previous
--- 0n Checksum  This is an optional "Checksum" field. The checksum is the low 7 bits of the sum of all preceeding bytes in the message following the "Message Class". 
--- F7 End of SysEx 
The "Control Levels" are used in the request message for this packet:
0n - Number of Control Levels (lo nib) (Nibble 1 of argument)

0n - Number of Control Levels (lo mid nib) (Nibble 2 of argument)

0n - Number of Control Levels (hi mid nib) (Nibble 3 of argument)

0n - Number of Control Levels (hi nib) (Nibble 4 of argument)

0n - Control Level A (lo nib) (Nibble 5 of argument)

0n - Control Level A (lo mid nib) (Nibble 6 of argument)

0n - Control Level A (hi mid nib) (Nibble 7 of argument)

0n - Control Level A (hi nib) (Nibble 8 of argument)

0n - Control Level B (lo nib) (Nibble 9 of argument)

0n - Control Level B (lo mid nib) (Nibble 10 of argument)

0n - Control Level B (hi mid nib) (Nibble 11 of argument)

0n - Control Level B (hi nib) (Nibble 12 of argument)

...

To request the Class ID number for Program - EQ - 1 Band (M) - Gain ) on a system with the Device ID set for 0, send:

               request  Num Control   Level A
----header----  type      levels      (Program)
F0 06 09 00 06  03 00  04 00 00 00  00 00 00 00

Level B        Level C        Level D
(EQ)         (1 Band (M))     (Gain)
02 00 00 00  01 00 00 00   02 00 00 00    F7