Play a MIDI module & sounds from a controller keyboard

I have a MIDI issue I haven't been able to quite figure out on my own. I have a Motif ES6 connected via "MIDI handshake" (MIDI In to Out, MIDI Out to In) to my MPC 3000.

However, I also have a MIDI module I would like to play on the Motif and record the notes into the 3000 sequencer... while the notes from the Motif play.

Is this possible?

What am I missing here? Do I need a dedicated MIDI controller keyboard for playing the module if I want the Motif notes to sound at the same time as the module? Or is it just the MIDI connections that are wrong?

I hope you understand my question; I can clarify if need be. Thanks.

Its never Midi IN to OUT, its always MIDI OUT to MIDI IN
The Midi OUT transmits data and the Midi IN receives it.

Xandre wrote: record the notes into the 3000 sequencer... while the notes from the Motif play.

I don't understand, Are you just trying to record into the 3000?
If so the connections I believe have to be from the 3000 Midi Out to Midi In of your Motif and vice versa and from the Motif to the midi module its Midi Thru (motif) to midi in (midi module). BTW a midi device may only have up to 128 notes.