SLOP(OPCS) Optical Printer Control System SLOP(OPCS) NAME slop - configure 'slop correction' for sloppy hardware (eg. faders) SYNOPSIS slop [chan] [steps] EXAMPLES slop d 300 # indicates the fader has 300 steps of 'slop' DESCRIPTION SLOP tells the software to take up slop for a motor whenever it is told to run in a prescribed direction. The sign of the [steps] arguments tells the software which direction it should prefer to take up slop in. A positive number takes up slop when the motor moves in a positive direction, a negative number takes up slop in the negative direction. To determine how much slop a motor has, disable any slop commands for the motor. Use JOG(OPCS) to move the motor in one direction. Now change directions, making note of how many steps you can tell the computer to run in the new direction before the equipment starts to actually move. Use this number of steps in the SLOP(OPCSDEFS) command for that motor, and note how the software trys to take up the slop. If the motor is being moved by a command in the direction the software wants to take up slop, the software will move the motor that many pulses BEYOND the position requested, and then back that many pulses to take up slop. This technique ensures the equipment is always resting on the same edge of the sloppy equipment, which can allow accurate positioning of even the sloppiest mechanics. NOTES For those of you who think it is a waste to have to take up slop EACH TIME the motor turns in the predefined direction, and that 'it should only take up slop once..when it changes direction', think again, pal. You are assuming the slop distance is a fixed entity, which it rarely is. In order to arrive at positions properly, the position must be found by always leaving off having moved to the position FROM THE SAME DIRECTION, so that the equipment is always left off resting on the same side of the equipment slop. This necessitates always doing the double-move slop take up whenever the motor moves in one of the two directions. BUGS none. SEE ALSO INTERP(OPCSDEFS) GO(OPCS) ORIGIN Gregory Ercolano, Los Feliz California 12/15/89