I have an Access Virus TI synthesizer that I would like to assign to a MODX8 with a MIDI connection. I tried and partially succeeded, but the thing worked the other way around. The voice of MODX is now coming from Virus TI. How can I set this to work the other way around? I would like to use MODX to play the voice of Virus TI. In Motif XF Song mode, was I able to set the MIDI channel that Virus TI was talking about, how do I set it up with MODX? I would like to use the MODX sequencer to set some tones for MIDI part with Virus TI 16 multitimbral.

When connecting any two keyboards via 5-pin MIDI, the sound comes the synth tone generator that makes the sound. (You would need to connect both devices to your sound system). MIDI is not sound... it is a series of coded messages...

The device connected MIDI Out to the MIDI In of the second device, is referred to as the MIDI master keyboard.
The device receiving MIDI In is said to be slaved to the master keyboard (20th century terminology).

If, for example, you connected the 5-pin MIDI Out of the MODX to the 5-pin MIDI In of your other device. You could then setup so that when you played the MODX Keys both the MODX would Output sound from its Main L/R Outputs and the external device would Output its own sound through its own audio Outputs.

Yes, both units would be outputting sound at the same time - through their own outputs.
Both units would output sound but only when you played the MODX Keys. Playing the other (slaved) device, would let you hear only that device.

Now, if you go into the MODX and set “LOCAL CONTROL” = OFF, then only the external MIDI connected device would sound when you played the MODX Keys. Understand LOCAL CONTROL as the parameter that determines if the MODX Keys are going to trigger the MODX Tone Generator. OFF disconnects them.
[UTILITY] > touch “Settings” > “MIDI I/O” > here you will find the MIDI In/Out setting = MIDI (5-pin), and LOCAL CONTROL On/Off.

MIDI CHANNELS
You must match the master keyboard’s Transmit Channel with the slaved device’s Receive Channel.
The MODX has its own system of Channel assignment designed to create (transmit) data that when captured and played back, makes sense to the MODX.

Important to know:
Any Device that is a keyboard with MIDI will normally send Out MIDI messages for every key you press, every controller you move, etc. This data allows you to record your musical performing to a MIDI sequencer, and then play that sequence back — it will have every note you played, every control you touched, etc., and it will faithfully recreate your playing to the smallest detail.

The point is — each device, as a priority, normally outputs this data which is designed specifically for itself. It knows what every messages is, and it can even decode the messages created *exclusively* for its own *system*. These messages would not be understood by a product made by a different manufacturer, and would not even be understood by a different model from the same manufacturer. These are called “System Exclusive” messages. The MODX sends many, many such messages... so to intelligently control an external device, you can setup a Performance Part slot to address your external device... you can program what sound it recalls (if it is capable of receiving program Change messages), you can transpose it, Note Limit it, you can even decide which of the MODX controllers will work with the external device.

Why am I telling you this?
Because when you want to use the MODX as a Master Keyboard controller you will want to build a Part slot in your MODX Performance that is designed specifically for the device you want to control via MIDI. This way you can better determine what it does... you can design a different setup for every Performance. (There are even ways to integrate the external device into the MODX’s Motion Control Engine).

This “Zone Master” function, lets you create a Part slot, that instead of addressing a ‘local’ MODX sound, you will turn the internal sound to OFF, and set the Part slot to TRANSMIT OUT via MIDI on a channel that matches your slaved device’s MIDI Receive Channel.

We should mention, the MODX is capable of transmitting on as many as 8 MIDI Channels simultaneously (one from each linked KBD CTRL Part). When using the MODX with external sound modules you can setup for various types of combinations (on a per Performance basis) —
Where you are just playing the external device
Where you are playing both devices, layered or split across the MODX keybed
Where you use the MODX to send program changes to the external device, but NOT trigger it
Etc., etc., etc.

You can read all about setting up your MODX for Zone Master control in the following article — the article applies to both the MONTAGE and the MODX.

Link: Zone Master - FAQ