Power I-Mig250P, Burn back knob

[Ray]

Can someone explain what the burnback knob on the Power I-Mig 250P, does? It has both arc force and burnback knobs and it looks like the Burnback knob in calibrated in, seconds? not sure and the manual doesn't seen to mention it. I thought at first it was like a post wire feed, but it doesn't seem to be.

[performance]

It provides burnback control of course.

It does it by keeping the wire energized for a given time after the feeding stops. This allows the stick out to burn back to a predetermined length without having to clip and trim.