Brunstein Observatory

Kreiensen, Germany

The Remote Control Concept


How it came to life

During some observations I thought it to be a good idea to be able to remote control the camera and possibly even the Super Polarix DX mount from a warm place. But unfortunately there are about 20 Meters between the observatory and the house. This means that a keyboard and monitor extension cable would not be a good idea. The only possible way would be some kind of remote access to the computer via a network. But this is not very easy with DOS.

At this point my first thought was to start programming a simple interface to the camera control box running under LinuX. I started programming with TCL/TK and C but when I wanted to run the first checks with simple image display work (there was luckily no other function implemented yet) I had to update the 486 computer with a proper version of LinuX. At this point i decided to reinstall LinuX from scratch as the old version was too old to be updated in a sensible way. While setting up the installation options a saw a thing which caught my interest: together with DOSEMU a function called XDOS was mentioned.

After finishing the installation of LinuX I then started to configure the DOS emulator. I knew that CCDOPS was running with it but the old versions I had tried so far did not include X11 support. At this point I was lucky - thanks to SBIG the CCDOPS software uses standard SVGA calls which are supported by DOSEMU using the XDOS command. This is what came out of this test phase:

The remote setup

The Pentium is running X11 with LinuX in my living room. A network connection has been established between the Pentium and the 486 in the dome using a simple coax cable (RG58) and two NE2000 network cards. A remote login is performed on the 486, xdos is started.

CCDOPS is running under XDOS, the X11 interface of the DOS emulator which is available with LinuX. When the environment variable DISPLAY is set properly any X11 output can be send via a network connection to a host computer. This means that the 486 is running CCDOPS, controlling the camera via RS232 and sending the display stuff back to the pentium. Image 1 shows the basic setup.

Remote Control Concept
Image 1

When this setup is used there is one restrictions: in graphics mode the fonts used by CCDOPS do not work with the X11 interface - but as I know what the software expects me to do in 99% of the cases and all basic setup can be done from the text mode this means no problem. When this was running I tried to do some more things with the emulators on the LinuX distribution: I tried WINE, the windows emulator. When doing some tests I found that wine has improved very much as well. A lot of standard windows programs (like Word6, Excel, even the filemanager) can be started and used. The filemanager even works on the linux partition as long as short filenames are used! But that was not the point. Lucky enough I found even GUIDE5 working with the emulator. Click here to see the X11 screen with GUIDE5 and CCDOPS running (CCDOPS runs on a remote computer!). Although the menu colors of GUIDE look something strange and wine displays some warnings it really works satisfying.

A typical observing session

When an observation is done this way these steps have to be taken care of: If you need some more information about a similar setup for your computer feel free to contact me. The image of the Dumbell Nebula from the first light image page was taken this way.

A look ahead

Well, maybe you just read about XCCD. XCCD is an X11 software so you just do not need the DOS emulation any more. The basic setup is the same though...

Back to the english index page...