REP(OPCS)		Optical Printer Control System		REP(OPCS)

    NAME
        rep - repeat current projector/camera shooting ratio (interlock)

    USAGE
        rep [count]			# repeat current ratio [count] times.
	    OR
	rep [device] [>frame]		# repeat until [device] gets to [>frame]

    EXAMPLES
        rep 4          # repeat the current ratio 4 times
        rep -4         # repeat the current ratio IN REVERSE 4 times
	rep >4         # repeat ratio until camera gets to frame 4
	rep pro >4     # repeat ratio until projector gets to frame 4

    DESCRIPTION
        The REP command shoots the current projector/camera ratio set by the 
	last RAT command. The camera ALWAYS exposes BEFORE the projector, so 
	when REP is executed, the frame already in the projector's gate is 
	exposed first. Example:

	    rat 3 1  rep 3

	...set up a 3 to 1 ratio, and shoot it 3 times. The camera FIRST 
	shoots 1 the frame in the projector's gate, then the projector 
	advances 3 frames... camera 1, projector 3, etc. After execution, the 
	projector runs a total of 9 frames, the camera a total of 3 frames.
	This command is effectivly the same as:

	    cam 1 pro 3  cam 1 pro 3  cam 1 pro 3
	    -----------  -----------  -----------
	         1            2            3

    NOTES
	Shooting at a ratio of 1:1 (or -1:-1) is faster than shooting with
	the equivalent commands cam 1 pro 1 repeatedly, because REP will
	run the camera and projector together.

	If you use the absolute specifier '>', REP will repeat the current
	ratio in the direction necessary to get the camera or projectors 
	to the specified frame. You can tell REP which motor you want to
	get to the specified frame by specifying any of the following after
	the REP command: CAM, PRO, PRO1, PRO2. Thus:

		rep pro2 >34      # run until pro2 reaches x34

	If you do not specify a device, the camera is always assumed:

		rep >34           # run until camera reaches x34

    TANDEM SHOOTING
	With old mechanical printers, you had to put the projector out half
	phase before doing a 1:1 shoot (aka. "INTERLOCK") and then back again
	after you completed the shoot. You DO NOT have to worry about this
	when using the REP command; this is done automatically.

	At the start of a 1:1 run (camera AND projector running together),
	the projector will stand still (remain seated) for the camera's first
	1/2 rotation rotation to get the camera and projector's movements in
	phase.  Both motors then run together for the duration of the shoot
	with the movements in phase until the camera shoots its last frame.
	At this point the camera stops with the shutter closed (unseated),
	and the projector will continue moving an extra 1/2 rotation, leaving
	a SEATED, UNEXPOSED image in the gate, as usual.

    FADE/DX
	If there are any pending fades or dissolves, the fader will FIRST
	move to its next position before the camera exposes a frame.

    AUTOFILT/FEED
	If AUTOFILT(OPCS) is enabled, the camera will first expose the filter
	in the gate before moving the filter wheel. (As with the projector,
	when the system is idle, the frame in the gate is /about/ to be shot)

	If FEED(OPCS) is enabled, the motors will /first/ move to position
	before the camera exposes a frame. (Similar to fade/dx)

    ALLSTOP
	Hitting the ALLSTOP button, usually the (`) key, will halt the
	motors at the nearest frame. ALLSTOP is safe during shooting; 
	it does not affect exposure, and always leaves the shutter closed
	after stopping. The allstop key can be redefined by ALLSTOP(OPCSDEFS).

    BUCKLE/VIEWER
	The camera WILL NOT RUN if the buckle is tripped. When exposing film,
	it also won't run if the viewer is open. If either condition occurs
	while the camera is shooting, the motors will stop with an error at 
	the nearest frame, similar to ALLSTOP.

	If 'hardware no' is in effect, the buckle/viewer state is ignored,
	so that the OPCS software can run on remote computers that are not
	pysically connected to an optical printer.

    TENSION MOTORS
	Before the camera or projector move, the appropriate tension motors
	are enabled, to ensure take-ups are in correct modes for film motion.

    COUNTERS
        The default 'big' frame counters (See BIGCOUNTERS(OPCSDEFS)) are
	limited to 6 digits. If a counter clocks above 999,999, or below
	-99,999, the display recycles to zero. This is only true of the 
	display..the software still keeps track of the real position.

	This is NOT the case if 'BIGCOUNTERS' is disabled; numbers in the 
	'small counter' display will not be clipped. Disable BIGCOUNTERS
	in the opcsdefs.opc if you need frame counts above 999,999.

    BUGS/TODO
	Needs a -cont flag, to continue rep commands that
	didn't finish shooting, ie. rep >50 dxo 10 rep -cont >60

    SEE ALSO
        RAT(OPCS)           - set the shooting ratio for the REP command
        REP(OPCS)           - shoot current projector/camera shooting ratio
	PROPHASE(OPCSDEFS)  - sets projector phase adjustment for 1:1 shooting

    ORIGIN
	Gregory Ercolano, Los Feliz California 11/29/89
© Copyright 1997 Greg Ercolano. All rights reserved.