Method to control a printing process in an inkjet printing apparatus, and printing apparatus to execute such a method

A method for controlling a printing process in an inkjet printing apparatus that has multiple print heads arranged substantially along a line oriented perpendicular to a movement direction of a recording material, comprising the steps of:

• generating a line scan to print a print line with said line of said print heads on said recording material, determining a mechanical mounting offset of each of said print heads relative to said line scan prior to printing, and said line scan measuring relative movement between the print heads and the recording material;
• individually controlling the individual print heads with each said mechanical mounting offset relative to the line scan to correct for the respective mechanical offset by a timing of the ejection of the printing ink from nozzles of the print heads, print data prepared for the printing with the print heads being stored in a memory device upstream of the print heads;
• transferring print data units to be printed by the individual print heads from the memory device to the respective print heads in a same order with which they are printed on the recording material;
• and
• controlling the order with which the print data units are transferred from the memory device to the print heads by means of request commands that are entered into a FIFO memory, wherein each request command identifies a print head and the order of the transfer of the print data units corresponds to an order of the request commands in the FIFO memory.