Ardour has automation modes for many of its controls. As of version 5.9, OSC can control what automation mode a fader uses. (See Automation.)

The form of the automation mode command is:

/strip/[control]/automation ii ssid mode

The next version of Ardour will add /strip/[control]/automation_name is ssid mode_name as feedback. A surface may choose to use only the first character of the string (M, P, W or T) instead of the whole string (this is in git now).

The touch mode needs more input so there is a Touch command as well (added post 5.9). It is almost identical to the automation command:

/strip/[control]/touch ii ssid touch

The only difference is the last parameter is 1 for touched and 0 for touch released. All of the rest of the explanation above applies.