Sync and Video : Working with Synchronization : SYNC Setup and Timecode Offsets in the Session Setup Window : Timecode Settings

Timecode Settings
Freewheel
The choices in the Freewheel section let you configure how Pro Tools will freewheel, or continue playback if timecode is interrupted or corrupted. Use these options to protect against errors that can occur if your SMPTE timecode source has “drop outs” or temporary lost signals.
None
No freewheel is applied.
Frames
Sets a number of frames to freewheel, from 1 to 120 frames. This value defaults to 8 frames, which is the recommended setting for most applications.
Jam Sync
Lets Pro Tools trigger synchronization to incoming timecode, and continue to play back even if timecode input is completely interrupted. It can be useful if timecode is damaged, or has been accidentally erased from your source tape.
Pull Up/Down
When Pro Tools is used in conjunction with a Synchronization peripheral, or a qualified third-party peripheral that supports pulled sample rates, this option lets you “pull up” or “pull down” the current sample rate.
For general information, see the Pro Tools Sync & Surround Concepts Guide. For more information on applying pull factors in Pro Tools, see Pull Up and Pull Down.
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Remember, pull up and pull down are applied differently in different workflows. Make sure you check each project’s specific workflow before you begin your work.