Glenn,

My understanding of the SYSEX commands are hex data values, sent via midi, to set/alter parameters or functions of a HW/SW device. This can be a synth, or lighting equipment, etc.
The data is usually sent in bulk to perform things such as reset, reassignment of a channel, general initialization commands to factory defaults.

Each manufacturer will have specific data values to control internal functionality. In your example below:

F0 26 7B 33 00 0E 01 F7

F0 - Data is to be sent

F7 - Finished sending data

The values in-between are hardware specific. Generally, the 2nd pair of digits identifies the hardware manufacturer. I believe Yamaha used 43.

Anyway, most of this information will be supplied in the operations/technical manual of the equipment.

Hope this helps...

Mark