Printing system servicing

A method of performing a service operation on a printhead on a print bar comprising:

• moving a printhead service module to perform a servicing operation on printhead nozzles of a printhead on the print bar;
• positioning nozzles on an auxiliary printhead to align with printhead nozzles obscured by the printhead service module;
• and
• with a controller, transferring printhead control data intended for nozzle circuitry of obscured nozzles on the print bar to nozzle circuitry on the auxiliary printhead,
• wherein the controller is to modify the timing of the transferred printhead control data based on the horizontal distance between the printheads on the print bar and the auxiliary printhead,
• wherein the auxiliary printhead replaces printhead nozzles from more than one printhead simultaneously.

A printing system comprising:

• a number of printheads mounted to a print bar;
• a nozzle servicing module moveable across the length of the print bar to selectively perform a nozzle servicing operation on a group of printhead nozzles;
• an auxiliary printhead mounted to a printhead carriage moveable parallel to the print bar;
• and
• a controller to:
• perform a nozzle servicing operation;
• move the printhead carriage in synchronization with the printhead service module;
• transfer, during a printing operation, printhead control data intended for printhead nozzles on the print bar obscured by the printhead servicing module to corresponding nozzle circuits on the auxiliary printhead;
• and
• modify the timing of the transferred printhead control data based on the horizontal distance between the printheads on the print bar and the auxiliary printhead.