Or for touching up a chopper, few passes with either coarse rod or flat one and you can go back to chopping.
I recently came across a small carbide sharpener which I used to get dings off my 711 (there was nothing to split the wood on and I bumped into the bricks). With few passes there was no sign of them on the edge. Will dig up a link, or post pic or two when I get home. It's small & light, pretty good tool for maintaining edge.