OPCSHARD(DOCS)      Optical Printer Control System       OPCSHARD(DOCS)

    NAME
        opcshard - notes on rigging the OPCS hardware

A DESCRIPTION OF THE OPCS HARDWARE
Version OPCSK1.00 (Kuper card version)

    The OPCS system uses the kuper card to generate pulse streams
    to run the steps/direction inputs on the microstepper motor drives.
    Only 'steps' and 'direction' outputs on the Kuper card are used by 
    the OPCS software currently.

OPCS SOFTWARE REQUIREMENTS/LIMITATIONS

    In order to run the Projectors, Camera and Fader properly, they must
    be wired to the following channels on the Kuper card:

        KUPER	    OPCS
        CHANNEL	    CHANNEL	DEVICE EXPECTED TO DRIVE
        -------	    -------	-------------------------------
	   0		A	Aerial Projector
	   1		B	Main Projector
	   2		C	Camera
	   3		D	Fader

    Other channels such as focus and zoom have no requirements, and can be
    run off any of the other channels.

    The OPCS software was originally designed to control a maximum of 12
    motors. Even though the Kuper card can control up to 16 axes, the OPCS
    software can only drive a maximum of 12.

    OPCSk1.00 does not take advantage of the Kuper card's encoder feedback.
    Under normal use, motors should never stall unless there is some hardware
    problem, or the ramping values were not set properly.

    The software provides for inverting the direction of a motor if it runs
    in the wrong direction. See DIRXOR(OPCSDEFS) to correct this. Normally,
    if the DIRXOR bit for a motor is 0, the motor will turn clockwise when
    told to run 'forward' from the software. By changing the DIRXOR bit to 
    a 1, telling the motor to run 'forward' will make it run counter-clockwise.

    The OPCS software's definition file (OPCSDEFS.OPC file) can program
    any of the IBM's hardware ports to control/monitor the following
    functions:

	Function			DEFS command
	------------------		---------------------
        Film buckle			buckle
        Viewer Open			viewer
	Deenergize (unlock motors)	deenergize
	Allstop				allstop
	Motor Direction Inversion	dirxor
	Home Sense			(see HOME SENSING below)
	Set a bit on a port		setbit
	Clear a bit on a port		clrbit
	Invert a bit on a port		xorbit
	Tension motors			tension

    The software currently requires at LEAST a 25Mhz machine, or faster
    to properly update the motors. The software will display the error:

        FATAL ERROR: Sync Fault (probably lost positions)

    ...accompanied by some disagnostics data if it finds the CPU cannot
    keep up with the motors.

    The software relies on the Kuper card's timebase to compute accurate
    camera exposures. Therefore, the software will have exposures
    consistent from machine to machine, regardless of the CPU's speed.

HOME SENSING

    To be flexible as well as modular, the OPCS software does not
    have home sensing routines built in. Rather, it uses its ability
    to call external DOS programs to home the motors. Users can define
    their own OPCS commands to be other OPCS commands, or run external
    DOS commands.

    These HOME programs can be executed either during the software 
    startup (by setting it to execute from the OPCSDEFS.OPC file), or
    from the interactive command mode by the printer operator.

    Programs such as DRIVER.C (supplied by Kuper Controls) can be modified
    easily to home the motors, or they can be written as small assembly
    language programs. Usually, a HOME program is supplied with the system
    if home sensors were installed during installation.

© Copyright 1997 Greg Ercolano. All rights reserved.