Top-of-Form (TOF) Synchronization Overview


Top-of-Form (TOF) modes are used to synchronize print jobs with an external TOF signal provided by the OEM at the Media Timing Interface. Before printing can begin in any mode, pre-job servicing must be complete, the startPrinting command must be called, and the engine must transition to the PRINTING state.



Configuration
 

DFE (Digital Front End): The TOF mode can be selected from the "Top of Form" dropdown located in the Print Settings (gear icon) within the DFE. If this option is missing, it can be enabled by modifying the CustomInterface.json file:

    • File Path: C:\Navigator\Navigator\htdocs\DFE\Resources\CustomInterface.json
    • Settings to Enable:
      • "EnableBetaFeatures": true 
      • "ShowMemjetMJSSettings": true


System Default: A default TOF mode can be set in the hwparamstore.json file on DuraFlex systems, and the system settings interface for other devices. Settings set from within the Navigator DFE will override it. 


 

TOF Mode Descriptions


NONE

    • The external TOF signal is ignored. Printing starts as soon as preconditions are met.
    • Internal signals are used to synchronize the printheads.
    • Gaps between subsequent pages are determined by the interPageGap setting.

FIRST_PAGE

    • The first page waits for the TOF signal to transition from inactive to active before printing begins.
    • Subsequent pages are printed using the interPageGap setting for spacing, without waiting for a TOF signal.

ALL_PAGES

    • Each page of the job waits for an inactive-to-active TOF signal before it will print.
    • If a TOF signal occurs before a page has finished printing (a "missed TOF"), the next page will not print until another TOF signal occurs, likely resulting in a large gap in the output.

TRANSACTIONAL

    • This mode is intended for jobs where missing an external TOF signal is not permissible.
    • Like ALL_PAGES, each page waits for a TOF signal.
    • However, a "missed TOF" will cause the engine to enter a FAULT state and the rest of the job will be cancelled.