Abstract: Multiple motion controllers for controlling servo motors are connected by a digital communications link so that controlled axes of the motion controllers may be slaved together regardless of their physical proximity. A given controller broadcasts position or command signals on the communications link in response to a request report message from any other controller. A second request report message may stop the broadcasting to conserve link capacity. Time shifting implicit in the link messages is corrected by estimating the velocity of the master axis and extrapolating the position to the local axes' time of updating.

Abstract: A method and apparatus displays a plurality of representations of an environment. The method includes the steps of (a) providing an object structure having a first branch of object data structures that defines a first domain of the environment, a second branch of object data structures that defines a second domain of the environment, both a first object data structure of the first branch and a second object data structure of the second branching defining a particular article in the environment; (b) displaying a first graphical image defined by the first object data structure; (c) changing a feature of the first object data structure; (d) automatically notifying the second object data structure; and (e) displaying a second graphical image defined by the second object data structure, the second graphical image providing an indication of a feature change of the first object data structure.

Abstract: Multiple motion controllers for controlling servo motors are connected by a digital communications link so that controlled axes of the motion controllers may be slaved together regardless of their physical proximity. A given controller broadcasts position or command signals on the communications link in response to a request report message from any another controller. A second request report message may stop the broadcasting to conserve link capacity. Time shifting implicit in the link messages is corrected by estimating the velocity of the master axis and extrapolating the position to the local axes' time of updating.

Abstract: A programming aid for troubleshooting real-time motion control programs controlling servo motors employs a graphical control language in which functionally related groups of instructions are represented by icons displayed on a programming terminal and interconnected by sequence lines to indicate the order of the instruction's execution. The programming terminal receives the address of the instructions being executed and identifies this address to a displayed icon to modify the icon thus indicating the internal operation of the program on a real time basis with little interruption of the control process.

Abstract: Multiple motion controllers for controlling servo motors are connected by a digital communications link so that controlled axes of the motion controllers may be slaved together regardless of their physical proximity. A given controller broadcasts position or command signals on the communications link in response to a request report message from any another controller. A second request report message may stop the broadcasting to conserve link capacity. Time shifting implicit in the link messages is corrected by estimating the velocity of the master axis and extrapolating the position to the local axes' time of updating.

Abstract: The present invention enhances the resolution and quality of characters of a system receiving the information initially in the form of video display pixels and providing hard copy output. This is accomplished by storing at least three successive lines of video data in successive, parallel connected shift registers, applying the outputs of the shift registers to a decoder, and generating driving signals for the printer head. The decoder compares the pixels on the same line as well as in preceeding and succeeding lines that surround each specific input pixel to generate the printer head driving signals according to whether straight or curved line segments are to be formed. In effect, the printer increases the density of the information elements and simultaneously provides rounding off of character edges and smoothing of diagonals.