Hi,
 
I have Sonar X1 Producer and am trying to record my Roland TD-11 drum set using midi.  I have a Scarlett 2i4 midi interface with a Roland UM-ONE midi usb cable that I am using for the connections to my computer.  
 
If I just use the UM-one midi to usb connections and I can get the software to recognize and record each instruments as individual tracks as I play my set but there are latency issues.  I adjusted the buffer size, still had issues and read that I should get a new sound card or go through another midi interface to resolve this issue.  Now I am going through the Scarlett 2i4. The issue now is I can't get the software to recognize the drum set, or I am doing something wrong with assigning inputs or creating my drum templates for these devices.  
 
I am new to midi recording so there could be many mistakes I am making along the way.  Any information on my setup and troubleshooting or recommendations for how to record an electric drum set would be much appreciated.  
 
   Thank You

Hi, and welcome to this forum.
Make sure that your 2i4 is selected as MIDI input (when SONAR is open) in Preferences (P) MIDI.
And that you select the 2i4 as MIDI input on your MIDI track / Instrument track.
MIDI itself does not make sound, so you will have to assign a Vsti / soft synth to play back your MIDI.
This video might be of help, unless you think it is too long / tedious. 
It goes through setting up, and using soft synths in X1.
All the best.

You should not have a problem using the USB output of the Roland to your computer. If you have latency try bypassing all effects. That will probably be the cause of the latency. 
 
As well you should be able to also use DIN type MIDI connection, there should be no difference other than having the Scarlett involved, but that system should not cause a lack of communication. All midi notes will be transmitted and received.