Yes, changing the sign on the scale flips over the following PINs:
(all begin with hm2_7i92.0.encoder.00.)
position
velocity-rpm
velocity
the change has no effect on:
count
rawcounts
As it turned out, I fixed it another way. I had the ESD button connected to the encoder-B DB-25 P11 (14) input. I moved the ESD to my BOB #2 and left no input for encoder-B. This flipped the encoder.00 inputs to all positive and I was able to leave the encoder scale at +180..
Now I can thread again, so problem solved! Thanks for the help!