Please see Dome Setup and Slaving Setup if you have not already set up the dome and telescope.
Make sure that the Dome and Telescope have been properly selected. Note that a Telescope Simulator and Dome Simulator are available if you wish to experiment with the software without the hardware being present.
Click the Connect button. The dome and telescope should now be connected. If you get an error message, check the connections.
Note: if the shutter was not fully closed or fully open when the program was started, the display will indicate "Shutter Error" for the shutter status. This simply indicates that the shutter is in an unknown position. It will reset to normal when the shutter position becomes known; for example, if the shutter is closed.
Click the Open button. The dome should start opening within a few seconds. If the dome was set up with Park Dome Before Operating Shutter, the dome will first move to the Park position, and then start opening. As a result, the status may not report Opening until the dome is parked. The shutters will open in sequence, one after the other. Once both are fully open, the status will change to Shutter is Open within a few seconds.
If so configured, the dome will automatically find the home position upon the first connection. Otherwise this must be done manually by clicking the Home button. You will not be able to rotate the dome accurately until this is done, because the dome will not know where it is pointing.
Note that if the Dome Control Panel displays "Dome has not been homed", it does not necessarily mean that the dome position is wrong. MaxDome II automatically resets the position if the home sensor is detected. It also remembers the home position as long as power is present on the Rotation Controller, even if the computer is disconnected.
MaxDome II is designed to maintain knowledge of the dome position, even if the dome is rotated manually using the hand paddle. So you do not need to re-home after moving the dome with the paddle.
To send the dome to a specific azimuth, click the Go To button. Enter the desired azimuth and click OK. (The control panel supports altitude selection as well; this is not required for MaxDome and is therefore disabled.)
Turn on Slave Dome to Scope. The dome will now turn so that the slit is in front of the telescope aperture. If the dome turns to the wrong position, please see Slaving Setup. Some extra suggestions are listed under Troubleshooting.
You can connect an ASCOM-compliant control program to the ASCOM Dome Control Panel. In your telescope control application, select Dome Control Panel instead of the telescope. Now whenever the control program sends a command, it will be intercepted by the control panel and used to move the dome.
Applications such as MaxIm DL/CCD can connect directly. Some applications, such as TheSky and Starry Night Pro may require a plug-in to be installed. The ASCOM Platform installer should have notified you about the installation procedure for these applications during the install process.
For automated applications, the Dome Control Panel will report "slewing" if either the telescope or dome is moving as the result of a slew command. That way, you will not get an image of the inside of the dome if the telescope moves faster than the dome.
For sidereal tracking purposes the Dome Control Panel checks the telescope position every 10 seconds. If the telescope has moved enough to require dome motion, the dome is automatically moved. If the telescope is slewed from the hand paddle, then the dome will follow the next time a poll occurs. On a long slew the dome may stop and start repeatedly, depending on the telescope speed. This will not happen for commands linked through the Dome Control Panel.
The shutter can be closed at any time by clicking the Close button. The dome should start closing within a few seconds. If so configured, it may Park first before closing. Note however, that this does not permanently park the dome; if slaving is still turned on, the dome will move to synchronize with the telescope again.
We strongly recommend that, regardless of the limit switch interlocks, a visual inspection be made to ensure complete dome closure. This will ensure that the dome is secure against weather hazards. For remote applications a webcam can be used for this purpose. When there is any possibility of damage, it is unwise to rely on a single system, no matter how reliable!
If you wish to park the dome in a particular position, click the Park button. You can set this position by moving the dome to a particular position and clicking the Set button.
After ensuring that your telescope and dome are parked, you may wish to shut down the software. Disconnect your control program(s) first. Next click the Disconnect button in the Dome Control Panel to shut down the links to the telescope and dome. Finally, close the dome control panel.
It is strongly recommended that you mount easily-accessible master power kill switches in the observatory, for both the Rotation Controller and Shutter Controller. This will allow you to kill the motors if an unsafe condition occurs. When working inside the dome, be aware that the shutter or dome may move at any time, in response to a (possibly remotely triggered) command from the computer. The dome also rotates periodically during sidereal tracking. Keep clear of moving parts at all times.
The MaxDome II boards include 10A automatically resetting fuses. This is to protect against overcurrents that might be caused by short circuits or possibly stalled motors. If you see the power light slowly cycling on and off, kill the power and correct the problem.
The shutters are sequenced in a particular order, assuming that the upper shutter overlaps on top of the bottom shutter. If for some reason the shutters appear not to be sequencing properly, shutter motion will be stopped. Reverse the motion to clear the error.
MaxDome II has a safety feature for detecting loss of communications with the PC. The Rotation Controller will "time-out" if it has not received a message from the PC for ten minutes. This could indicate simply that the user closed the Dome Control Panel without closing the dome, or it might indicate computer failure or power outage. This safety feature is part of the reason we recommend using a trickle charged Gell Cell as the power source for the controller.
In the event of a failure in the communications link between the Rotation Controller and the Shutter Controller, the Shutter Controller can also be configured for a ten minute time-out. Do not turn this feature on if there is a risk that the shutter mechanism could collide with the telescope during the close cycle.
The dome can be set up to automatically park whenever a shutter open or close operation is requested. The dome will lock out rotation commands, rotate to the park position, operate the shutter, and then re-enable rotation commands.
Warning: all shutter safety features are disabled when the shutter is operated using the manual open/close switch. The shutter will move immediately, without parking; it is assumed you are present and watching for any mechanical interferences. The time-out closure feature will also be disabled, so that you can open the shutter for more than ten minutes without the PC link being present. Otherwise the dome would keep closing during manual operation.
If the rotation sensor does not see any dome rotation after actuating the motor for five seconds, the dome will be automatically stopped. To clear a rotation error, hit the Stop button, then issue a new rotation command. Note that an optical sensor failure will not prevent manual operation; the motor will continue turning under manual control even if the sensor does not see motion. This allows you to operate the dome manually if the rotation sensor fails.
MaxDome II expects the dome to stop rotating fairly quickly when a stop command is issued. Some domes may have significant inertia, and additional encoder tics may occur after MaxDome II commands the motor to stop. The Rotation Controller will watch for additional tics for several seconds. If the dome continues rotating for more than two seconds, it may cause problems with the pointing accuracy. If inertia is a problem, then the best solution is to slow down the dome rotation speed.
Note that the dome may not show "At Park" if it coasts too far past the park position. "At Home" will appear when the dome stops after a Home command, even if the dome is slightly out of position. The next command will clear the "At Home" indication. Also note that "At Home" and "At Park" status is only displayed after a command to Home or Park; these indications will not appear if the dome just happens to stop at those positions.