Description: The Observatory Settings (Slave Settings) dialog is used to define how the observatory will be slaved the the telescope position.  It defines parking as well as settings to slave the dome slit to the telescope.



  • Observatory Type - Defines the type of observatory.  Options are "Dome" and "Roll Off Roof".  When "Roll Off Roof" is selected the "Dome Geometry" section will not be accessible.
  • Dome Geometry - These settings are used to provide positional information when slaving the dome.  The units are not important provided that all measurements use the same type of units
    • Diameter at Equator - The diameter of your dome at the equator.  This should be measured from where your slit opening is.  For example if your dome is skinned on the outside you would measure from the outside diameter.  If it is skinned on the inside you would measure the inside diameter.  
    • North Offset - The offset from the center of intersection of the Right Ascension and Declination axis to the center of the dome.  If the RA/Dec intersection is north of the dome center this value is positive.  If the RA/Dec intersection is south of this location the value should be negative.
    • East Offset - The offset from the center of the intersection of the Right Ascension and Declination axis to the center of the dome.  If the RA/Dec intersection is east of the dome center this value is positive.  If the RA/Dec intersection is west of this location the value should be negative.
    • Vertical Offset - The offset from the center of the intersection of the Right Ascension and Declination axis to the center of the dome.If the RA/Dec intersection is above the dome center this value is positive.  If the RA/Dec intersection is below this location the value should be negative.
    • GEM Offset - The distance from the center of the Right Ascension axis to the center of the telescope.  This value can vary depending on how your scopes are setup on your mount.  It is best to use some trial and error here.  If the top of your scope is being eclipsed by your dome increase this value.  If the bottom of your scope is being eclipsed decrease this value.
    • Update Frequency - Number of seconds to wait between slew commands.  This also will depend on your Allowable Error (below).
    • Allowable Error - Number of degrees from where the dome azimuth can be from the calculated ideal position.  This will depend on the width of your slit as well as position in the sky.


  • Slaving Options - These options control special events with respect to parking and unparking of the mount.  
    • Slave on Sequence Start - This will cause the dome to automatically slave itself to the telescope (follow the telescope) when the sequence starts.  This is equiveleant to clicking the "Slave to telescope" box in the control panel.
    • Park Observatory With Mount - This will cause the observatory to park and unpark when the mount parks and unparks.  The Park and Unpark must come from Sequence Generator Pro to be captured.  If the park status of the mount changes outside of Sequence Generator Pro the observatory park status will not be updated.
    • Mount Unpark Opens Shutter - When the mount is unparked the shutter or roof will be opened
      • Open Shutter First - This will cause the shutter/roof to open prior to unparking the telescope.  Useful for Roll Off Roof designs where the telescope needs to be horizontal to allow for roof clearance. WARNING - Using this option to open your roof prior to unparking your mount is very risky!  It is highly recommended to  have other fail safe mechanisms in place that will prevent your roof from coming into contact with your telescope.  Main Sequence Software will not be held liable for any equipment damage.
    • Mount Park Closes Shutter - When the mount is parked the shutter or roof will be opened
      • Park Mount First - This is used to park the mount before parking the observatory.  WARNING - Using this option to park your mount before closing your roof is very risky!  It is highly recommended to  have other fail safe mechanisms in place that will prevent your roof from coming into contact with your telescope.  Main Sequence Software will not be held liable for any equipment damage.



It should be noted that when a slew is issued through Sequence Generator Pro that the slaving code will attempt to make an educated guess about what side of the meridian the scope will end up on.  Unfortunately there is no way of knowing which side of the meridian the scope will actually end up on for items that are very close to the meridian.  Sequence Generator Pro always assumes that the mount will end up on the opposite side of the pier from where it is pointing.  For instance if the object is West of the meridian the scope will be assumed to be on the east of the meridian.  However if this guess is incorrect the dome will be properly adjusted when the next update as it will use the side of pier obtained from the mount.  For this reason it is beneficial to set your mount driver to disallow slewing to the same side of the meridian that the scope is currently on.