Several safety features are built in to the design of the SkyRoof system.

These features are based on "Asimov's Laws" of robotics.

The basic laws being:


  • A robot may not harm a human being.
  • A robot must protect its own existence 


 Because some observatories do not have sufficient clearance to open or close the roof regadess of OTA position, SkyRoof has a low-level function built in to the controller

to prevent the roof from moving if the telescope OTA is not parked in a "Safe" position.On systems that do have sufficient clearance, the AtPark jumper wire loop should be connected to bypass this feature. On systems that do not have sufficient clearance, the wires should be connected to a suitable system or device that detects if the telescope OTA is in a position that it is safe to open or close the roof with the possibility of the roof striking the OTA.


One of the key safety features of the SkyRoof system involves the monitoring of the incoming weather data file.

Each time SkyRoof receives a fresh copy of the weather file, it examines the file in several ways.

Firstly, it checks the date stamp of the file to ensure that the file is recent and being periodically updated.

Next, it checks the format of the file to ensure that it is correctly formatted and the length of the file is normal..


 If SkyRoof detects an error, it will sound a audible alert to inform the observatory operator that an error has been detected, display a warning message on the computer screen, optionally transmit an email and/or SMS message and allow the user two minutes to correct the issue. If, after two minutes the issue has still not been corrected, the system will park the the telescope (providing the mount driver is connected) and close the roof.


 A park safety timer built in to the SkyRoof application monitors the amount of time that it takes for the telescope mount to reach the "parked" state after

"Park Scope" command has been issued, 

If, for some reason the telescope should take more than the specified time, SkyRoof will issue an email/SMS alert message to the user and display a message indicating that there may be a problem.


The SkyRoof app also has a "watchdog" timer that monitors the amount of time that it takes for the roof to open or close.

The first time that the SkyRoof application is commanded to open the roof, a timer within the program measures and records the amount of time that it takes for the roof to open. If, in the future for some reason the recorded time plus 25 seconds is exceeded, the program will display a "Roof Motion Error"

message and will subsequently generate and send out a text message and an email message if so configured.


 The SkyRoof controller has an on board “watchdog” timer that starts counting down from two minutes to zero whenever any ASCOM based program is used to open the roof. Each time the controller is polled (SkyRoof polls it every two seconds, ACP and Maxim poll it every one second and the others imaging programs are similar) the watchdog timer is reset to two minutes. If, for any reason, the controller doesn’t get polled, the watchdog will count down until it reaches zero and if the observatory has sufficient clearance to close the roof(or the scope is already parked) the system will then energize the roof close relay. 


It is important to note that if any work is to be carried out on the observatory, the user should open the roof using a mechanical switch instead of an ASCOM program to prevent the watchdog timer from starting and possibly closing the roof while the system is being worked on.


 















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