318 / | HD | ELECTRICITY: MOTIVE POWER SYSTEMS |
560 | DF | POSITIONAL SERVO SYSTEMS (E.G., SERVOMECHANISMS) {23} |
567 | DF | .~ Program- or pattern-controlled systems {3} |
569 | DF | .~.~ Digital or numerical systems {1} |
570 | DF | .~.~.~ Contouring systems {4} |
574 | .~.~.~.~ Multiple axes point to point systems |