Last night I tried to use the echo feature on my 2.4 (model 2242) to see what function I had my multi-function knob set for. The instruction sheet simply says hold down the set button and it will blink a mystical code. I assume it means to do this directly after turning it on and not while already in the menu tree somewhere if that makes sense. Tried it and it just flashes green, red, green, red......
I think I answered it myself. I had assumed this was a feature that would tell what the multi function knob was set for but I think it's used while already in the menu tree to find out where you are while programming.