The NexStar User's Guide - Excerpt from Chapter 5
The Slew Limits feature is designed to prevent the telescope, or equipment attached to it, from making contact with the tripod or base. On the NexStar 60/80/114, the optical tube can easily make contact with the tripod when pointing at objects high in altitude. With other models, adding a camera or longer optical accessories to the back of the scope might result in a similar situation. Slew Limits control the minimum and maximum altitude (angle from the horizon) that a slew can attempt without displaying a warning. To continue to protect your equipment even when mounted on a wedge, Slew Limits are measured in relation to the base of the telescope, rather than your local horizon.
Keeping in mind that 0° is the horizon and 90° is straight up, the following procedure will accurately the maximum Slew Limits required for your equipment:
The altitude displayed is your maximum setting for slew limits. For minimum, I recommend leaving the default setting of 0° in place.
To access Slew Limits, press the Menu button then select Utilities on the little NexStars or Scope Setup on the bigger models. Scroll to Slew Limits, press Enter and you will be presented with selections for minimum and maximum limits. Any future attempts to GoTo an object outside of your Slew Limits will result in a warning that can be ignored by pressing Enter, but if you do, closely monitor the telescope to prevent contact with the tripod or the base. If there is contact, your alignment will be lost and you will need to power off the scope and start again with a new alignment. Additionally, the motors in the larger NexStar models are strong enough to damage equipment if contact is not prevented.