is used to control or regulate the various work components of the workstation 29 as can be seen a creel thread 18 is fed to a thread 17 drawn off from a twisting pot of the twisting device 15 and is twisted with the latter to form a yarn 14 the yarn 14 arrives via a draw off device 16 and deflection means 22 at the steam setting device 1 in which as already indicated above the yarn 14 is thermally set the steam setting device 1 as conventional substantially consists of a yarn treating chamber 21 which is in turn divided into a central zone 5 and two end zones 6 and 7 the central zone 5 is in this case supplied via a connection 8 with a hot gaseous medium preferably saturated steam or hot steam while a cool gaseous medium for example compressed air is blown into the end zones 6 and 7 in each case via connections 9 a or 9 b the central zone 5 also has a connection 10 by means of which steam or condensate can be removed the yarn treating chamber 21 furthermore has a yarn inlet opening 2 in the region of the end zone 6 and a yarn outlet opening 3 in the region of the end zone 7 arranged in the yarn inlet opening 2 and the yarn outlet opening 3 is in each case a yarn sluice 23 a or 23 b which seals the yarn treating chamber 21 under excess pressure relative to the environment the yarn 14 thermally set in the steam setting device 1 is guided by a draw off device 11 and deflection means.