The Rotary Dies follow a Cam algorithm tied to material motion. When the material stops moving, the die stops moving. Also, if the material moves in reverse, the die will begin moving in reverse. The algorithm is only minimally able to handle material that is moving in reverse so it is only allowed for a brief period of time before an error is displayed and the controller will exit run.

On some lines we have noticed that when the material comes to a stop it may oscillate forward and reverse prior to coming to a complete stop. This causes nuisance errors. Additionally, there is concern that it may oscillate enough in reverse that it reverses the die back into the metal and then stops.

Two changes have been made:

1. During Coast to Stop mode, after the die leaves the metal and prior to it accelerating for the next target, reverse motion of the die is clipped such that the die will only advance with the material. It will not follow it in reverse. The material must proceed in the forward direction passed the point where the die stopped in order for the die to begin moving forward again.
2. The negative velocity error test becomes disabled when the controller enters Coast to Stop mode.