A central timing device for a printing machine includes an address generator in the form of a series of encoder disks arranged on a common shaft connected to the machine. The disks are provided with fixed coding indicative of angular increments relative to a reference point. The resulting binary words are applied as angular position addresses to addressing inputs of a programmable read only memory. Another device for generating addresses pertaining to momentary rotary speeds of the machine is selectively connectable to the addressing inputs of the PROM to read out at the output of the latter timing signals modified according to the rotary speeds.
