I've seen a youtube tut on how to patch in an external device and doing that involves a small util called the External Insert and that tool measures the latency and compensates for it - but I can't find that software. If it's part of Sonar, it's well hidden, I've checked every menu.
 
Thanks - rev

Cancel that, I found it. Right click in the FX bin and choose External Insert from the menu. 
 
rev