will be lowered and the drive will be switched back to a deceleration rate lower than the programmed value the rate of speed change will drop and a subsequent computation of the stopping distance will again raise the deceleration flag therefore a bang bang control of the deceleration is provided down to zero speed because of the time lag in the drive which occurs the first time the deceleration flag is raised a time advance factor is programmed in to compensate for this one time system 34 dead time 34 in the control to diameter configuration the anticipated stopping diameter is computed from the stopping distance to account for the possible layers slabbed off after a sheetbreak the caliper the last value of roll diameter before sheetbreak and the new diameter after run is resumed are used for computing the decremental footage the formulae for various computations are set forth below on the basis of the equation where d is equal to the distance v is the velocity and a is the rate of deceleration the stopping distance may be computed on the basis of the fortran language as the stopping diameter may be calculated in accordance with equ1 where v n 1 t is the speed of the roll in ft sec computed from the last sample based on a 500 ppr drum tachometer rate the decremental drum tachometer count may be calculated from the relationship the resolution of the drum tachometer is 1 500 or 0 2 therefore the resolution limit of layers is equ2 for example for a 30 inch roll and a caliper of 0 002 inch the resolution error is 15 layers of 118 feet the error in.