Dome Automation

ACE has a complete range of products and services for your observatory dome. The dome is perhaps the most vital element in a robotic system – it must be able to close under any conditions. We specialize in the automation of Ash Domes and large domes found at professional observatories.

The WIYN 0.9-meter telescope at Kitt Peak, powered by ACE SmartDome

Key Benefits

• Ramp-up Ramp-down variable speed UL listed frequency drive controller
• Control for up to 2 doors or a single door plus a windscreen
• Automatic shutdown for robotic observatories
• RS232 interface to your telescope controller
• Complete real-time feedback of doors status and motion
• Radio controlled version for use with minimal slip rings
• Radio-free version available for use in radio telescope facilities
• Interface with ACE Real-Time Rain-Snow sensor and weather station

Dome Controller

This module replaces the "drum switches" supplied by Ash Manufacturing Company. The photograph shows a controller for use with a main shutter door and lower dropout door. Rotation is activated by pressing the white LEFT RIGHT buttons. Real time status of the doors is displayed in the ACE SmartDome™ display. A twist-lock emergency stop button is provided for enhanced user safety.

The SmartDome controller box.

The dome controller has a RS-232 port for easy control from a computer. The controller has an AC frequency drive controller for precise control of the dome azimuth. Besides smooth starting faster rotation speeds (typically 1.5x to 2x) can be realized, making the observatory more efficient.

The lower control unit is typically located below one of the dome rotation motors. It requires a 240 VAC power supply (which is readily available in almost every building). It can either be installed into a circuit disconnect box or into a NEMA L14-20R twist-lock receptacle. ACE can work with your architect to ensure smooth installation.

The dome controller should be wired to its own dedicated 2-pole 20A circuit breaker.

Power is supplied to the rotating section of the dome by one of two methods:

Slip Ring Power Supply

Slip rings deliver power to the SmartDome controller and the motors in the rotating part of the dome.

A minimum of three power slip rings, installed by Ash Manufacturing Company at the time of the dome purchase, are required to get power to the rotating part of the dome. The three rails provide L1, L2 and ground for a 240 VAC system.

The upper controller communicates with the ACE SmartDome™ by radio. Real-time status of the dome doors is always available. Push buttons for opening and closing the doors are provided for manual backup in the event of a radio failure.

The photograph shows a typical control for a hydraulic dropout and three slip rings.

We can retrofit slip-rings for pre-existing domes.

ACE SmartDome™

ACE SmartDome™is an embedded microprocessor used to control the dome. All of the input-output lines are optically isolated

This is a sophisticated controller that has a wealth of commands yet is easy to program. It talks over a standard RS232 serial port.

It gives real-time status of the dome doors and dome azimuth.

It can automatically close the dome in the event of rain or in the event of a communications failure with the host (telescope control) computer.

Programming is very easy. For instance, to send the dome to a desired azimuth of 135 degrees send the command 135 MV. If the ACE SmartDome™ is turned ON then in the event of a communications failure a watchdog timer will automatically close the dome after a predetermined (programmable) amount of time. Automatic dome encoder calibration is just one of the many rich features found in this product. The dome azimuth is displayed together with a ← or → symbol to show the last direction of rotation. So the photograph shows the dome has reached an azimuth of 350º and that is got there by rotating left.

Five low-brightness LED's are on the front of the controller. TX and RX show the transmit and receive of the RS232 and flash as data is present. The group of three LED's marked ON, AS, and CH are lit when AUTO-SHUTDOWN in ON, an AUTO-SHUTDOWN is in progress, and the dome is CLOSED and HOME.

A partial list of commands are shown below.

The RS-232 interface is shown below

The most common thing to do is send a ? command to the controller. This does two things. First, it resets the watchdog timer and tells SmartDome™ that the host computer is still alive. Second it sends back a short status report for use by the control system. Real-time information on the status of the dome doors, any motion of any motor, and the azimuth provides complete feedback for both robotic and interactive observatories.

ACE provides complete installation services for dome control products and pre-installation consulting to ensure smooth system integration. Please contact ACE as soon as possible, preferably while making the decision on your dome purchase.

Dome Software Interface

The ACE Robotic Control System has complete dome control integration.

The dome setup dialog for the ACE control system.

The following dialog shows the setup menu for the dome. Note that the software handles alt-azimuth and fork-mounted equatorials where the azimuth of the dome equals the azimuth of the telescope and also off-axis equatorials where the azimuth of the dome is significantly different from that of the telescope. Accommodation for odd geometries, where the telescope is not centered in the dome, is also catered for.

Moreover, the software optimizes the placement of the telescope within the dome slit and calculates the azimuth that the telescope must reach before an occultation occurs. For domes with a dropout system it calculates if the dropout needs to be down (useful for windy nights or local light-polluted areas) and which part of the dome will get in the way.

We welcome your call to discuss your complete observatory requirements.

ACE 0.61m robotic telescope with fully integrated dome, weather and instrument control.