This command toggles File change polling for the active file. This can be very useful for log files or any other files that might be dynamically updated. When file change polling is enabled, the active file is automatically checked periodically based upon the time interval set in Settings » File handling » File change detection and updated with any changes that have been made to the file.
The file change polling drop down will be grayed out in the "View" tab unless the associated Settings item Poll for file changes at force interval in seconds in Settings » File handling » File change detection has been set to a value greater than 0.
UltraEdit Wiki