Mixing : Plug-In and Hardware Inserts : Plug-In Automation and Safe Modes

Plug-In Automation and Safe Modes
All real-time plug-ins can be fully automated, and support all Pro Tools Automation modes (Write, Touch, and Latch, plus Trim).
The Auto button opens the Plug-In Automation dialog, where you can enable individual plug-in controls for automation recording (see Automating Plug-Ins).
The Safe button engages Automation Safe mode. When enabled, existing plug-in automation is protected from being overwritten (see Record Safing Plug-In Automation).