Abstract: A communication circuit supports a first communication protocol and a second communication protocol that is different from the first communication protocol. A number of signals include first signals conveying first information messages and second signals conveying second information messages. The first information messages include a repetitive message having fixed repeated content and the second information messages include a non-repetitive message having variable content. The first signals and the second signals are transmitted via the communication circuit using the first communication protocol for the first signals and the second communication protocol for the second signals.

Abstract: A method and apparatus for inspecting an annular or ring-like work element to determine if the concentricity and wall thickness of the work element is within prescribed limits. The work is mounted within a rotatable drum so that the outer wall of the work resides in contact against the inner wall of the drum. The drum is rotated about its axis at a speed such that the work is caused to rotate about its own axis of rotation in one point rolling contact with the moving drum surface. An electrical contact point is placed at a prescribed distance from the axis of the drum and is adapted to close a warning circuit in the event the concentricity or wall thickness of the work element is outside of the desired limits.