A method for controlling a roller line, preferably a cold roller line, which has one or more roller stands each with two working rollers, which form a roller gap, through which a roller band is transportable. One or both working rollers can shift relative to the other, so that the roller gap is adjustable. The method includes making available a reference speed, which is a parameter for controlling the roller line, measurement of speed of the roller band before the inlet into the roller gap, measurement of the thickness of the roller band before the inlet into the roller gap, and adjustment of the roller gap of one or more roller frames in the roller line on the basis of measured speed and thickness before the inlet into the roller gap as well as the reference speed.

A slit plant comprises a rest bar (14), for regulating the transversal position of an inlet guide to the molder unit (12), a rolling unit for reducing the billet to a rolled section having two sections, a cutting box (13) for separating the two sections into two separate strands, one or more rolling units for rolling the two strands (1, 2), pairs of speed and/or section measurers (20, 21) downstream of the cutting box (13), a shear (15). The method for controlling the plant provides measuring the rolling speeds V1 and V2 of each of the two strands (1, 2) and/or of the respective sections A1 and A2 of the two strands (1, 2) downstream of the cutting box (13) by means of pairs of measurers; detecting the lengths of the two strands (1, 2) and calculating the difference in length thereof, based on which the plant, in a successive feedback step, is activated to decrease the difference in length between the two strands (1, 2).