What FADERs are you talking about?

On my controller m audio axiom pro. I want to assign the midi channel volume on the mx49 to the faders on my m audio axiom pro.

I was doing some research and I saw something about midi channel volume being cc007. So I would assign the each fader to program change with cc 007?

Am I on the right path?

On my controller m audio axiom pro. I want to assign the midi channel volume on the mx49 to the faders on my m audio axiom pro

For support on your m audio axiom pro, you would do well to ask them.

If it sends Control Change 007 that will control the volume of everything on the current MIDI channel.
Not sure what you mean by "program change with cc 007" because Program Change is an entirely different class of message from cc (Control Change). Maybe that's just a typo... ?

There was another similar thread at https://yamahasynth.com/forum/midi-controller-with-sliders-to-control-volume-of-performance-parts.
Effectively, if I understand that thread correctly, I don't use midi control change CC 007 messages to control part volume. Instead, the external axiom pro would have to send sysex program change messages to control part volumes. Does anyone know if this is what the Yamaha Faders iOS app uses to independently control part volumes on a MX?
I'd like to use an external control surface like a Korg nanokontrol2 2 midi fader module to control my Mx88. Are some midi control surfaces fully programmable to assign fader so they send sysex messages instead of sending CC 007 control change messages? However, if each part has a separate midi channel, then perhaps CC 007 will change only the volume of the part corresponding to the midi channel for the fader? Anyone know about external USB midi fader control surface compatibility with MX synths?

Instead, the external axiom pro would have to send sysex program change messages to control part volumes.

Hmmm! I doubt that is really necessary but I don't know the device you speak of...

System Exclusive is a type of system wide message, that can be used to address specific products, by brand, model, and can address specific parameters within the device with very precise hexadecimal messages.

Program Change is a type of channel specific message, that when preceded by a Bank Select (Control Change) message can change a device to a specific program on the specific MIDI channel. Unlike sysex, the PC message must be on the MIDI channel being addressed.

Volume is a separate type of message falling under the channel Control Change type. And must be made on the specific channel it is going to affect.

So when you say "send sysex program change messages to control part volumes" that says a mouthful but really says it's going to earn you a MIDI Jedi Merit Badge just to setup a controller... shouldn't be that difficult. Imho

If you can create System Exclusive messages, then perhaps you can fashion a message that does all of that... but to be of assistance we would need to know what you wish to recall, specifically.

A couple of years ago Yamaha had a free App called "Faders & Pad" (although I no longer see it listed) it was 8 Faders assignable to any CC message on any channel. That would give control over 1-8 in the first setup and 9-16 in the second setup. (Hmmm, don't know why it seems to have disappeared... but if you downloaded it during the initial free period, find it, I find it an awesome little utility with scores of useful things it can do). Today I only see the "Yamaha Faders" - which gives you four Faders at a time...