Notes on Digital Dome Works Hardware/Interface
Installation of DDW hardware
- The Instruction Manual (in a black 3-ring binder) seems very thorough and clear. There are several loose pages in the front pocket of the binder with hardware installation instructions specific to Ash Domes. Chapters 1 and 2 of the bound pages have general installation instructions. The appendices include schematic diagrams. The CD-Rom with the dome control software also has an electronic version of the manual. (The disc is in the back pocket of the binder.)
- 6/5/09 Tim from RiteWay installed the DDW box. It is currently running from a standalone 12 V source, but we'll incorporate the dedicated 12 V source once it's installed. The box also takes 220 V power from the same source as the dome rotation. Next up is testing it with the computer.
Hardware for Computer Interfacing
- Dome controller communicates to computer via serial cable (RS232). Standard CAT 5 cable is sufficient for this use for runs up to several hundred feet. When making long cables, refer to Appendix 2 of the manual for wire, plug and jack color conventions for the RJ14 (standard telephone) plug.
- USB-serial adapters have been successfully used by the manufacturer. They have not tested controlling the dome software and telescope/camera software simultaneously via a multi-port USB hub. (Doesn’t mean it can’t be done. We’d need to try it out.) Installing a serial port expansion card in the control computer is always an option, of course.
- 6/5/09 EJ tried a USB-to-serial adapter for controlling the TCC box. The adapter tried (Keyspan / TrippLite USA 19HS) worked OK when connected directly to the computer - could control the TCC via COM 4. But it did not work when connected through the Icron USB remote hub. This seems independent of the TCC - the Keyspan adapter test utility couldn't open the serial port even when nothing is connected. Icron suggested trying a different adapter. We have one on order that's made by Digi / Inside-Out Networks; it's an Edgeport model. We'll see if that works. Docs/drivers for the Edgeport are at the Digi support site. We have a local copy of the documentation.
Controlling DDW Software with TheSky
- The DDW Control Program has an option to allow dome control via TheSky. DDWCP will check a designated text file to which TheSky writes the current telescope RA and Dec and move the dome to match. One minor inconvenience which may arise once we get everything up and running is that TheSky only updates the text file when it is in “focus” (i.e. its program window is on top of other windows). If we ultimately control TheSky via MaximDL, we may need to briefly bring TheSky in focus when slewing to a new object so that the text file updates and the dome control software knows to move the dome.