4  Telescope Control & Data Acquisition Computers

4.1) Introduction

4.2) Basic Operating Instructions

4.2.1) Turning the machines on

4.2.2) Rebooting from a computer "crash"

4.2.3) Turning the machines off

4.3) The Telescope Control Computer

4.3.1) Logging on

4.3.2) Directory structure

4.3.3) Disk storage space

4.3.4) Starting the Telescope Control Software

4.3.5) Restarting individual windows

4.4) Some Useful Info

                    4.4.1) Internet Access

                    4.4.2) Storing Data

4.5) Quick Look and Data Reduction

4.1  INTRODUCTION

There are three "user" computers at the 2.4-meter telescope (in addition to special-function computers described in later sections of the manual):

1. mdm24ws1: Linux workstation. This is the main observing workstation, providing telescope and instrument control windows.  There is another workstation, mdm24ws2 that can be used for accessing data to perform data reduction and transfer.  Typically, all access to hiltner is performed through either of these workstations.

2. hiltner:  Linux workstation.  This system provides instrument and control interface. It is also used for control of the RETROCAM system.  Most interactions with hiltner will be through mdm24ws1.  

3. DFM TCS Control PC:  This Win10-based system is used for telescope and guider control as well as the interface for the primary mirror AC system and temperature and humidity metrics.  It also allows user-interface to the telescope through the amateur astronomical program, TheSky.

All of the computers are networked together, with the raw data disks shared among the computers to provide direct access to the data from any workstation.  Raw data are written to /lhome/data on hiltner but can be accessed via the workstations by pointing to /data/hiltner.  If using one of the MDM CCDs (Templeton, Nellie, Echelle), data are written to the CCD-interface machine (mdmarc1) and can be accessed via the workstation by pointing to /data/mdmarc1.

All computers share a networked PostScript laser printer (b&w) and their main home and data disks.

In addition, there are network ports available for connecting a laptop computer to the network as a guest machine. Connections are GB (fiber).  Power users can mount the home and data disks on the mountain machines readonly using SAMBA with the standard username and special SAMBA password written on the white board. A short-range wireless network is also available in the common areas at the 2.4m and 1.3m telescopes for wireless-equipped laptops.

All computers can also communicate via the mountain network with their equivalents at the 1.3 m McGraw-Hill Telescope.

4.2  BASIC OPERATING INSTRUCTIONS

4.2.1  Turning the machines on

Under normal circumstances the computers and their peripheral devices are left powered on at all times. The only time an observer will need to power up the machines from a cold start will be after a serious storm or a hardware failure.

With the exception of the monitor and keyboard, the Linux computers are located in the computer room racks and the power switches are on the front of the computers.  

To start the machine(s) go through the following sequence:

• Turn on the monitors on all machines.

• Turn on the mountain server, mdm, if it is not already on.

• Turn on the Caliban disk enclosure, IC (if in use), then hiltner.

• Make sure the HP network printer is turned on.

• If using the facility CCD cameras power up mdmarc1.

4.2.2  Re-booting from a computer crash

Occasionally you will need to recover from a crashed or hung computer. Try to logout in the usual manner. If this fails try to issue Control-C a few times to see if you can get a response. If the system is still hung, reboot it as follows:

1. Press Ctrl+Alt+Del. The computer will halt, shutdown various services, and hopefully at the end reboot automatically.

2. If you are trying to power-down the computer, wait until you see the computer start the reboot, and then hit the power switch.

4.2.3  Turning the machines off

4.3  The Telescope Control Computer

The telescope and MIS box can be coordinated remotely using programs running on mdm24ws1. Each program has a separate command window. This section contains all the information you need to control the telescope (xtcs) and MIS box (xmis2).  The guider is operated by a stand-alone Windows PC.

4.3.1  Logging on

The computers have a screen blank feature to stop image burn-in on the monitor. The screen goes blank if there is no activity after a certain period. Move the mouse or press any key (e.g. a Shift key) to activate the monitor.

If the windows are operating on the data acquisition computer (mdm24ws1), there is no need to log on. Skip this section. Otherwise, hit the Enter key and the login prompt will appear.

• The observer username and current password are on the white board in the control room. The password changes regularly.

• If you typed the password correctly, you will receive a brief welcome message and X-windows will launch in about 5 seconds.

• On the Linux systems we have adopted the KDE window manager for all data-taking and data-reduction accounts. Please do not change the desktop environment (e.g., to Gnome), as this is guaranteed to make it impossible to run certain key applications.

• Facility staff will typically set up the telescope for a new observer, or after an instrument change.  Observers should not attempt to run setup procedures unless specifically instructed to do so (e.g. over the phone while handling a problem after-hours).

4.3.2  Directory structure

You can find out what is in a directory with the command ls.

To change from one directory to another use the command cd, for example:

   cd <cr>   (go back to the home directory)

   cd /data/hiltner/obs24m <cr>  go to hiltner's data scratch area
  

Raw data for various instrument are written to data directories as follows:

   OSMOS, MDM4K, R4K, CCDS and TIFKAM: /data/hiltner (on hiltner, /lhome/data)
   CCD Cameras (Owl):  /data/mdmarc1 (on mdmarc1, /home/data)
   MDM8K (detcom): /data/vesuvius/obs24m

4.3.3  Disk storage space

To find out how much disk space is used type the command df -h in a terminal window. The last three columns of the table report the remaining available space, the used percentage of the disk capacity, and the disk identification. You can also use the KDiskFree tool on hiltner to monitor disk usage graphically in real time.

We advise that you make a daily backup of your data. DVD drives are available on mdm24ws1, mdm24ws2 and hiltner.  Quicker yet however, is to simply plug in a USB-connected external drive, or a flash drive at the FX100 Remote Access Device for mdm24ws1.  Data can then be easily moved over using a file management program.

4.3.4  Starting the Telescope Control Software

The TCS system and peripheries (JSkyCalc, MIS and instrument control software) are linked from a program called "bridge" on mdm24ws1. To start, click on Applications, then Telescope Control and choose xtcsBridge.  A terminal window will appear on the desktop.  The observer should not have to interact any further with this window.

If you are using one of the MDM facility CCD cameras, or one of the OSU instruments (OSMOS, MDM4K, R4K, CCDS or TIFKAM), you also need to start the xmis2 program which controls the Multiple Instrument System or MIS. To start xmis2, click on Applications, then Telescope Control and choose xmis2.  The GUI window will appear on the desktop.

4.3.5  Restarting individual windows

You might need to re-start an individual window if it is accidentally destroyed (!) or if it crashes. Remember that windows (and especially icons) can be hidden under other windows.

If a window hangs do the following:

If you think that the window has genuinely crashed or is absent, enter the command jobs. If the window name appears as a stopped job, kill it with the command kill %n where n is the stopped job number displayed to the left of the job name. Also issue the command ps -x to list all the processes that belong to the obs24m user. If the window name appears in the list, kill the process with the command kill nnnn (or kill -9 nnnn) where nnnn is the process number. Repeat the ps -x command to check that the process was indeed destroyed.

Keeping the number of extraneous windows to a minimum will increase the efficiency of the computer. 

4.4  SOME USEFUL INFO

4.4.1  Internet access

MDM has regular access to the Internet through a 10GB fiber link making it possible to ssh or scp to a machine at your home institution or elsewhere.  Due to variable network usage on Kitt Peak, actual data transmission rates can be significantly lower than the theoretical maximum. In addition, you should be aware that MDM is billed a significant amount based on its actual fraction of the total Kitt Peak network traffic. For these reasons, the Internet is suitable only for transfer of small data files, but it can be quite satisfactory for checking weather reports and satellite images, and otherwise killing time on cloudy nights.  

4.4.2  Storing data on DVD

For writing DVDs, put a blank disk into the DVD drive and then launch the k3b program. The k3b program uses a standard drag-and-drop interface to let you build up a set of files to burn onto DVD, then burn the disk.

We recommend burning data onto disk at one time, rather than using so-called "open" disk formats which are prone to failure leading to loss of data. DVD media are cheap, so don't worry about not filling up an entire 4Gb disk at one time. We also recommend burning backup copies before you leave.

4.5  QUICK LOOK AND DATA REDUCTION

mdm24ws1, mdm24ws2 and hiltner all have the latest versions of XVista (v7.x), IRAF 2.12, SAOimage ds9 (works on 24-bit displays, unlike XImTool), etc. All are familiar tools and are extensively documented.

To find data through an IRAF terminal, point to /data/hiltner (for OSMOS, 4k detectors, CCDS or TIFKAM) or /data/mdmarc1 for MDM CCDs (Templeton, Nellie, Echelle), ModSpec, or the MkIII.