Abstract: An apparatus for controlling a mechanical system in response to messages from a host computer system. The apparatus includes a conventional communications link for communicating messages from the host computer system to a motion control processor and interface and driver circuits for converting digital signals generated by the motion control processor in response to messages from the host computer system into control signals having appropriate waveforms and timing for controlling a particular mechanical system. The motion control processor is programmed to perform a number of tasks in accordance with a schedule downloaded from the host computer system. The host computer system downloads profiles which consist of series of segments consisting of data structures which define elements in the mechanical system to be controlled, identify functions to be performed and include necessary data.

Abstract: A plurality of acceleration tables consisting of a sequence of step times defining intervals between steps and thus an acceleration profile to be executed by a stepper motor is stored in a first memory. A step table defining a sequence of excitation patterns for driving a stepper motor is stored in a second table. Identical DMA channels output the step times to a timer and an exitation pattern to a buffer. The timer measures the duration of the step times and when each step time expires generates a trigger signal which initiates the transfer of the next step time and next excitation pattern through the respective DMA channels. The buffer outputs are inverted to form bipolar signals to drive current drivers in accordance with the excitation pattern. The apparatus is initialized by a data processor to select one of the plurality of excitation tables to drive a selected motor.