Speeds above 6 or even 8 degrees per second are possible with the right motors/gear reduction/driving voltages.
Initialization of date/time/location, and align with one or several stars. Align with one-star to quickly get going or more stars to correct for polar axis misalignment, cone error, mount construction errors, etc. for more accurate gotos and tracking. Tracking can optionally compensate for refraction and mount geometry errors, one or both axes.
Home commands including the ability to move the telescope to the home position and stop tracking or reset the controller when at the home position for initialization. OnStep even supports home switches, so it can automatically orientate the mount at the start of operation.
Parking functionality includes the ability to set the park position (anywhere you like), park, and to unpark. In addition to placing the telescope in the orientation you designate this saves the alignment model (as long as the mount isn't moved) and PEC index position.
Meridian flips can happen automatically as needed. The latest (OnStepX) supports setting the side of pier and predicting which side of the pier a goto will end up on. It also supports automatic Meridian flips at near 0 hours (at the Meridian limits E/W) and under the pole near 12 hours (at the Axis1 Min/Max limits,) provided the overlap allows the destination to be reached.
The guide commands are for pulse-guiding, centering objects, etc. Pulse-guide rates are remembered between sessions. Standard guide rates always reset to 20x sidereal at startup. Backlash compensation is supported and can optionally be disabled during pulse-guiding.
PEC commands include the ability to record, play-back, read, and write PEC data. PEC is supported only on equatorial mounts, usually with worm/wheel gears. An index sensor is not required but is supported so OnStep can always recover the worm zero index without a need to park.
Encoders for are supported via the Smart Web Server integration with OnStep. These provide pointing correction and the ability to manually move the telescope without OnStep losing track of the mount orientation.
Rotator support allows for automatically positioning camera angle and optionally countering Alt/Az field rotation.
Focuser support includes backlash and optional temperature compensation.
The latest (OnStepX) supports physical limit switches and software limits for all axes (mount, rotator, and focusers.)
Auxiliary feature support includes control of switches, analog outputs (EL panel for flats,) and dew heaters. Dew heaters can be simple or dew-point tracking for effective temperature control of secondary mirrors in the optical path.