The DGX-650 can send and receive MIDI on all 16 channels, but when it comes to sending MIDI it depends on what you're sending and how the keyboard is set up.
As long as the "Keyboard Out" function is turned on, the following voices will be transmitted on the following channels:
Main Voice -- Channel 1
Dual Voice -- Channel 2
Split Voice -- Channel 3
You can't change those channel assignments-- however, if you're sending the MIDI to a DAW then it shouldn't matter what channel the data is being sent on, anyway, because in the DAW you simply choose the desired MIDI In device port (i.e., the one for the DGX-650, which I assume is something like "Digital Piano-1") for which track you want the DGX-650 to go to. I'm not familiar with Logic Pro, but most DAWs that I am familiar with automatically default to "All Channels" when you select a MIDI In device, although you can of course change that to a specific MIDI channel. Then, if you want the received MIDI data to be passed on to a MIDI Out device port, you can select the channel you want it to be sent on-- e.g., you could send MIDI data from the DGX-650 to the DAW on channel 1, then send it from the DAW to some MIDI Out device on channel 2 (or 3, or 4, or 5, etc.).
Just to be clear, channel 1 on any given MIDI port is different (distinct) from channel 1 on all other MIDI ports-- i.e., each MIDI port has its own set of 16 channels, which are separate from the 16 channels of every other MIDI port. This might be a little confusing if you're used to using MIDI DIN connections where you connect one MIDI device directly to another MIDI device, because in that case the channel numbers do have to match-- unless you've got some sort of unit that can process MIDI events between the two devices, in which case the MIDI event processor can be set to change the channel numbers on the events. A DAW has a kind of MIDI event processor built in-- at least, it should if it's a half-decent DAW, which I'm certain Logic Pro is. It might not be able to do all the things that a fancy MIDI event processor can, but it can certainly change the MIDI channel numbers on events as it receives those events from one MIDI device and forwards them to another MIDI device.
However, if for some reason you really want the DGX-650 to send MIDI data on a different channel than 1, and all you need is one voice (i.e., no split), you can transmit on channel 2 or 3 as follows:
Channel 2 -- Turn on the Dual Voice, set its Volume and Octave, and tell the DAW to receive only channel 2.
Channel 3 -- Set the Split Point to the last key on the keyboard, turn on the Split Voice, set its Volume and Octave, and tell the DAW to receive on channel 3.
You can also send MIDI data on other tracks if you're sending a song playback or style accompaniment to the DAW.
For a song, turn on the "Song Out" function (which doesn't work with the built-in songs because they're protected), and the MIDI data from the song will be sent on all of the channels which the song uses.
For a style, turn on the "Style Out" function, and the MIDI data from the style's parts will be sent on channels 9 through 16.
Getting back to "Keyboard Out," some DAWs let you limit the received Note events to a specific range. If Logic Pro lets you do that, you can use it to create splits and layers beyond what the DGX-650 allows-- e.g., you might be able to do something like the following:
Track 1 -- MIDI In = DGX-650, channel 1, notes 21 through 35 --> MIDI Out, Device X, channel 1 (Track 1 is one split on Device X)
Track 2 -- MIDI In = DGX-650, channel 1, notes 36 through 47 --> MIDI Out, Device X, channel 2
Track 3 -- MIDI In = DGX-650, channel 1, notes 36 through 47 --> MIDI Out, Device X, channel 3 (Tracks 2 and 3 are layered together as a second split on Device X)
Track 4 -- MIDI In = DGX-650, channel 1, notes 48 through 59 --> MIDI Out, Device X, channel 4 (Track 4 is a third split on Device X)
Track 5 -- MIDI In = DGX-650, channel 1, notes 60 through 71 --> MIDI Out, Device X, channel 5
Track 6 -- MIDI In = DGX-650, channel 1, notes 60 through 71 --> MIDI Out, Device X, channel 6
Track 7 -- MIDI In = DGX-650, channel 1, notes 60 through 71 --> MIDI Out, Device X, channel 7 (Tracks 5, 6, and 7 are layered together as a fourth split on Device X)
etc.
Of course, that depends on the capabilities of Device X. Or you could forward to multiple MIDI Out devices and/or virtual instruments.
