Apparatus for determining whether a valve is fully opened or closed. In one embodiment a valve position translator includes a cam tube and a rod. The cam tube has a cylindrical wall. A first slot in the wall is disposed along a radial arc of the tube. A second slot in the wall extends from an end of the first slot at an angle acute to the first slot. The rod extends through the wall, and rotates the cam tube while moving linearly along the cam tube in the second slot and while moving in an arc in the first slot.