Yes. MIDI connections and signal transmission are available.
MIDI messages are sent when you use buttons or knobs on the DJM-A9. You can send MIDI clock messages too.
For details on output terminals, connections, etc., see the [USB/MIDI Section] in the Instruction Manual.
The Instruction manual is available [here].
The list of MIDI messages is available [here]
Note: The DJM-A9 does not support the input of MIDI signals.