Celestron CGX 700 Maksutov Cassegrain Telescope Celestron PWI Telescope Contro - Page 18

• Backlash - This selection allows you to set the backlash compensation for each of the mount's axes of motion. Mechanical gears have a certain amount of backlash or play between the gears. This play is evident in the amount of time it takes for a star to move in the eyepiece when reversing slew directions. The amount of gear backlash is constant, so with the slower slewing rates, it will take longer for the star to move in the eyepiece when reversing directions. CPWI's anti-backlash feature allows you to compensate for backlash by inputting a value that quickly rewinds the motors just enough to eliminate the play between gears. The amount of gear backlash is different in each mount, so you will need to experiment to determine the best value for your mount. Most mounts work best with values between 30 and 70. It is generally better to have a value that is too small than too large. If the value is too large, you will see the object overshoot when you change directions, which will make it hard to center objects in the field of view. NOTE: Gear backlash compensation is only recommended for visual use and may be counterproductive when used during astrophotography. When tracking is enabled, the mount will be moving in one or both axes. Pressing a direction button opposite to the direction of tracking will cause the gear backlash compensation to activate twice; once when you push the direction button, and again when you release it and tracking resumes.) To set the anti-backlash value, enter a value from 0-99 for both RA and Dec (or AZ and ALT). CPWI will remember these values and use them each time you turn the telescope on until the values are changed. If you do not want to use any backlash compensation, make sure the value for each axis is 0. • RA Slewlimits (EQ mounts only) - This selection allows you to set how far beyond, or how far before, the meridian the mount will slew in RA before requiring a meridian flip. This functionality is especially useful during astroimaging, as you may want to track an object through the meridian for as long as your mount allows before performing a flip. To use the RA Slewlimits, first select the "Enable" checkbox, then set the limits for East of the meridian and West of the meridian. Negative numbers indicate the number of degrees past the meridian. The limit is -20° since most Celestron EQ mounts cannot slew further than 20° past the meridian due to mechanical limitations. A positive number indicates a meridian flip will occur before the mount reaches the meridian. +40° before the meridian is the maximum value allowed. (NOTE: It is important to know the mechanical limits to motion past the meridian for your mount before these limits are entered, otherwise you may reach the mechanical limit before the software slew limit, which may cause you to need to realign the mount.) (NOTE: AZ mounts on EQ wedges do not have a limitation on how far past the meridian they can slew.) • Altitude Slewlimits (AZ mounts only) - This selection allows you to the define the allowable slew range in the altitude axis. This can be useful for preventing accessories attached to the rear cell of the mount from hitting the base of the mount when the telescope is pointing straight up. To use the altitude slewlimits, first check the "Enable" box. Then, set the lower limit and upper limit to the altitude slew range (0° is the horizon, 90° is zenith). • AutoGuider Rates - This selection allows you to set the autoguiding rate as a percentage of sidereal rate. This is helpful when calibrating your telescope to an autoguiding camera for long exposure astroimaging. • Tracking - Choose from sidereal, solar, or lunar rates. The current tracking rate selected will appear in the "Mount State" section of the Data bar at the top of the screen. For EQ mounts, you can also activate tracking in both axes by selecting the "Ra + Dec Tracking" checkbox. This can be useful to use if your polar alignment isn't very good. • PEC - Enables PEC playback for mounts that support it. (See Train PEC below.) • Meridian Sweep (EQ mounts only) - This function instructs the mount how to respond to GoTo commands when slewing to objects that are near the meridian. It can be used to prevent unwanted meridian flips. Meridian Sweep allows the telescope tube to remain on a desired side of the mount after slewing to the object. (NOTE: If the RA Slewlimits are enabled, they will provide a limit to how far past the meridian the mount can go until a meridian flip is performed.) (NOTE: AZ mounts on an equatorial wedge do not require this function, as they do not need to perform a meridian flip.) Once enabled by selecting the "Enable" checkbox, there are three options: • Favor East - If the target object is accessible from both sides of the mount, selecting "Favor East" instructs the mount to GoTo to the object as if it were on the east side of the meridian. The optical tube will then be positioned on the west side of the mount and pointing east. • Favor West - If the target object is accessible from both sides of the mount, selecting "Favor West" instructs the mount to GoTo to the object as if it were on the west side of the meridian. The optical tube will then be positioned on the east side of the mount and pointing west. • Favor Current - Selecting "Favor Current" instructs the mount to favor whichever side the mount is currently on when slewing to objects close to the meridian. The "Angle" selection box allows you to choose how far past the meridian the mount can slew during a GoTo command before the meridian flip is performed. Make sure the number you enter in this box is less than any negative slew limit if RA Slewlimits are enabled. If RA Slewlimits are not enabled, then make sure the "Angle" is less than the number of degrees that your mount can move past the meridian before mechanical interferences occur. • GoTo Approach Direction - Use this setting to change the direction of the mount's final approach when slewing to an object. You can change the approach direction for each axis of the mount. For EQ mounts, RA positive means the mount 16