VELREP(OPCS) Optical Printer Control System VELREP(OPCS) NAME velrep - special purpose velocity repeat patterns for tandem shooting USAGE velrep [filename] [repcnt] 'filename' is the name of a '.vrp' file (format described below) that contains the commands to define the velocities necessary for tandem shooting. 'repcnt' is the number of times to loop the velocity patterns defined in the .vrp file. DESCRIPTION This command lets advanced users define very specific velocity patterns to send to the motors for precise tandem-motor shooting, such as shooting YCM B & W separation masters at full speed. Basically, any situation where shooting with separate cam and pro commands is too slow. The .vrp file defines which motors will be running. Normally this command is not executed directly by camera operators; typically a custom OPCS 'runcmd' command is defined to invoke velrep to implement shooting operations. This way, the runcmd programmer can hide the filename, which the camera operator shouldn't have to deal with. For instance, one might define a 'ycmshoot' command in the OPCSDEFS.OPC file as: runcmd ycm ycm.run 1 ..and creating a one-line 'ycm.run' file that contains: @velrep ycm.vrp $1 Then the operator can just type 'ycm 10', and this will invoke the more obscure command 'velrep ycm.vrp 10' behind the scenes. EXAMPLE velrep campro.vrp 5 # repeat the campro.vrp pattern 5 times THE .VRP FILE FORMAT <label>: # text label used to identify blocks of vels 0 0 0 # vels, one for each channel (a, b, c..) -10 0 0 # '-' prefix indicates run in reverse 10+ 10+ 10+ # '+' postfix indicates increment/decrement the # frame counter by 1. Inc or dec depends on the # vel's direction; 10+ will inc, -10+ will dec. 0! 0 0 # '!' postfix (in 'a' chan ONLY) does 'allstop check' # (if true, jumps to <label> for 'allstop <label>') # 'allstop <label>' must be defined if ! specified. # Check is done AFTER these vels are sent to motors. goto <label> # where to go next after last vels sent repeat <label> # if repeating, go to <label> allstop <label> # if allstop occurs, jumps to <label> to stop the motors # Only one 'allstop <label>' allowed in entire file. # '!' postfix indicates where to do the allstop check. tension +1 +1 -1 .. # Sets directions motors are primarily running, # either +1 (fwd), -1(rev), or 0 (still) for each chan. done # return to OPCS, shooting completed o Lines whose first character starts with a '#' are ignored. These are comment lines, and are not parsed by velrep. o Each line should have no more than 256 characters. o Always checks for BUCKLE and VIEWER as part of allstop checking.
FUTURE o Add a way to specify BUCKLE/VIEWER/TRIP checks in the .vrp file. ORIGIN Gregory Ercolano, Altadena, California 12/15/03