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

4.3.6) The Mouse buttons

4.4) Some Useful Info

4.4.1) Internet Access

4.4.2) Storing Data on DVD

4.5) Quick Look and Data Reduction

4.1  Introduction

There are three "user" computers at the 1.3-meter telescope (in addition to special-function computers described in later sections of the manual):

1. mdm13ws1: Linux-based workstation used for telescope and instrument operations and data acquisition.  There is another workstation, mdm13ws2 that can be used for accessing data to perform data reduction and transfer.  Typically, all access to mcgraw is performed through either of these workstations.

2. mcgraw: PC running Linux OS.  This is the Telescope Control Computer (TCC).

3. etna: Pentium PC running RedHat Linux 6.1 configured to run the MDM8K CCD mosaic camera. It runs the detcom program and is generally remotely accessed from chichon when observing.  This computer is rarely used as it is exclusive to MDM 8K operations.

All of the computers are networked together, with the raw data disks shared among the three computers to provide direct access to the data. Raw data are written to /lhome/data on mcgraw but can be accessed via the workstations by pointing to /data/mcgraw.  If using one of the MDM CCDs (Templeton, Nellie, Echelle), data are written to the CCD-interface machine (mdmarc2) and can be accessed via the workstation by pointing to /data/mdmarc2. The raw data disk on etna is called /data/etna/visitor, and has a capacity of approximately 70 Gbytes.

A network printer (b&w) can be found in the observing room and can be accessed by the workstation machines.  It is also possibly to connect personal computers to the printer once on-site.

In addition, there are network ports available for connecting a laptop computer to the network as a guest machine. LAN connections are GB, however going off-site currently routes through a T1 connection, limiting bandwidth to less than 2 mbs. There is also wireless.

All computers can also communicate via the mountain network (via ssh and scp) with their equivalents at the 2.4-m 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 thunderstorm 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 mcgraw, power switch on the front of machine (all of mcgraws's disk drives are internal).
• Turn on the power to etna: power up etna using the switch on the front panel labeled "POWER" (only if using the 8k)

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

1. If using etna (MDM8K), login to the console as user "shutdown", password "haltsystem", and it will turn itself off.
2. Power off the Linux workstations mcgraw and hill by logging in as a regular user and typing "shutdown" at the prompt. Answer "Y" at the prompt. They should turn themselves off.  If not, shut them down via the front panel power switch.
3. If using one of the 4k detectors or CCDS, quit out of the data-taking program on the IC (type "quit" at the prompt), then turn off the power on the PC after you see the DOS prompt return.

   Leave the machines on unless there is bad lightning in the area.

Caution - If you are cycling power on a computer (turning it off then back on again), always count slowly to 10 between "off" and "on" to prevent possible hardware damage (you need to give disks time to spin down, and various electrical systems time to discharge).

4.3  The Telescope Control Computer

The telescope and MIS box can be controlled remotely using programs running on mdm13ws1. 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 (mdm13ws1), there is no need to log on. Skip this section. Otherwise, hit the Enter key and the login prompt will appear.

• The observer user name is "obs13m", and the password is posted on the dry-erase board in the control room. It changes regularly, so don't bother recording it.

• If you typed the password correctly, you will receive a brief message, and the XWindows will start.  

• 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

When opening a terminal window on mdm13ws1, the "home" directory is:

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/mcgraw <cr>  go to mcgraw's data area
  

4k detectors and CCDS data are written to mcgraw (/lhome/data).  On mdm13ws1, data can be found linked at /data/mcgraw.

Templeton, Echelle, and Nellie data are written to mdmarc2 (/lhome/data).  On mdm13ws1, data can be found linked at /data/mdmarc2.

You must change to the desired directory each time you bring up a new window. To find out where you currently reside issue the command pwd (print working directory).

4.3.3  Disk storage space

To find out how much disk space is used type the command df. The last three columns of the table report the remaining available space (kbytes), the used percentage of the disk capacity, and the disk identification.

We advise that you make a daily backup of your data to DVD, or better yet, external hard drive.  There is a DVD drive on hill.  External hard drives (and flash drives) can be connected to the breakout box located by the workstation monitors via standard USB cable.

4.3.4  Starting the Telescope Control Software

The TCS system is controlled from mdm13ws1 using the MDM 1.3m TCS program. To start, click on Applications, then Telescope Control and choose MDM 1.3m TCS.  The GUI window will appear on the desktop.  Initialize.

To start xmis2, click on Applications, then Telescope Control and choose xmis2.  The GUI window will appear on the desktop.  For more information on operating the xmis2, click here--Multiple Instrument System.

If you are using the MDM8K camera, it has its own filter wheel system and the MIS will not be mounted on the telescope.

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 the 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 visitor 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. 

4.3.6  The Mouse Buttons

The mouse menus are kept as simple as possible, and are the same on all of the MDM computers (allowing, of course, for features not available on all machines).

The three mouse buttons are assigned as follows:

Left Button:

Main Menu - Click and hold this button to get a pull-down menu with the most relevant programs and xterms available on the system.

Middle Button:

Window Ops - commands to manipulate windows (move, resize, iconify, kill, etc.)

Right Button:

Desktop Control - lose track of one of your windows? Click and hold the right mouse button, and then select the window you are looking for. It will bring that window forward and put the cursor in it.

A couple of special "hot" keys are also available on the keyboard:

Linux workstations:

"F1" key (top rank) is used to move windows forwards and back (equivalent of the Sun "Front" key).

"F2" key (top rank) will open and close windows (equivalent of the Sun "Open" key).

Additional window operations:

To change the font size in an xterm window:

Hold down the Ctrl key and then click and hold the Right mouse button inside the window. A pop-up window ("VT Fonts") gives you options ranging in size from unreadably small to huge. The default size is medium.

To disable/enable the scroll bar:

Hold down Ctrl and the Middle mouse button ("VT Options" menu), and select "Enable Scrollbar". If a check-mark appears next to the words, you have a scroll bar; if not, you have none. A lot of other options are available here as well.

4.4  SOME USEFUL  INFO

4.4.1  Internet Access

MDM has regular access to the Internet through a T-1 line (1.5 Mbps) that is connected through the Kitt Peak mountain network, 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.  Furthermore, due to the speed limitations of the T-1 line, it certainly is better to transfer data to disk or external drive instead of over the network to your home institution.

4.4.2  Storing data on DVD

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Updated: 2016Apr13 (Galayda/MDM)