CHK(OPCS)		Optical Printer Control System		CHK(OPCS)

    NAME
	chk  - check if the pro/cam/fader counters are at certain values

    USAGE
	chk  [pro] [cam] [fader]            # single head printer
	chk  [pro2] [pro1] [cam] [fader]    # dual headed printer

    EXAMPLES
	chk  10  13'12  0
	     |     |    |
	     |     |    Check if fader is closed
	     |     Check if camera counter reads 13 feet 12 frames
	     Check if projector counter reads '10'

    DESCRIPTION
        "chk" verifies counter values are where they should be.
	Useful in RUN(OPCS) scripts to help catch errors during in script
	programming and shooting.
        
        If a check fails, an error warns of the discrepancy, prompting
	the operator with an ABORT/CONTINUE option.

	Arguments can be either in frames or in feet/frames format.
	Arguments can also be selectively bypassed with '-', example:

	    chk - - 170       # only check if fader at 170 degrees
	    chk 120 - - -     # only check if pro2 counter reads 120

    EXAMPLE
        Assuming the counters read: PRO=34, CAM=12, SHU=0, and the following 
	command is executed from a running script:

	    chk 34 10 170

	...all running scripts will be stopped, and the following errors will 
	be generated (because the camera and fader are not in the positions
	that were specified):

	    CHK:  Camera not at 10 frames
	    CHK:  Fader not at 170 degrees
	    Hit any key to continue  (ALLSTOP TO ABORT)

    HISTORY
        CHK(OPCS) is the old command limited to only checking cam/pro/fader.
	CHECK(OPCS) is the newer command which can check any channels
	including motion control channels.

    SEE ALSO
        CHECK(OPCS)    - newer command that can check all counters
	RUN(OPCS)      - run an OPCS script file
	MOTORS(OPCS)   - enable/disable motors for debugging scripts

    ORIGIN
	Gregory Ercolano, Los Feliz California 11/29/89