FAQ

You have to be in the Unix group "nstx". At the Unix/Linux prompt, type "groups" to see if nstx is one of the groups you are in. If not, send e-mail to unixadmin@pppl.gov.

Path variables are different on the nstxpool and portal computers so you may have to update your login scripts for RedHat Enterprise Linux.

Is NoMachine the best thing to use to log into the Linux cluster?

NX NoMachine has become very popular here for accessing the Linux cluster. After you disconnect and reconnect later, even from a different location, your Linux desktop and all the windows are in the state you left them (assuming the Linux computer was not rebooted). See NX Suppport for instructions.

I don't like using X-windows; how can I use the MDSplus tools?

You can read data into IDL, from a terminal session, and plot with Tektronix graphics (see below). NOTE THAT VERSATERM DOES NOT WORK AT PPPL, as of February, 2006, SINCE TELNET IS CONSIDERED INSECURE!!!

You may want to use some of the Web Tools available.

I'm having problems with my X-terminal or X-emulator. What should I check?

The most common problem on a unix/Linux system is not having your DISPLAY variable set properly. Many forms of remote login automatically handle "X-forwarding" for you (e.g.,ssh); if not, you need to set the environmental variable DISPLAY yourself. If you receive an error similar to the following when trying to run an X-windows application like scope,

    Error: Can't open display:

You need to set your environmental variable DISPLAY:

    setenv DISPLAY where.to.plot:0.0

(replace "where.to.plot" with your network name or TCP/IP number, e.g., 123.123.123.123)

Another typical problem is "access control," i.e., the computer that tries to send an X-window must be allowed to display it on your screen. Many X-terminals require that access control from specific nodes be granted explicitly. On your Unix login computer you may grant access using xhost or xauth (see the man pages for these). Type xhost at the Unix system prompt with no arguments to see if access control is enabled, and which clients are authorized. If you want to authorize the display of X-windows from europa.pppl.gov, for example, you could include the following in your login script (e.g., ~/.login when using the csh or tcsh shells):

    xhost europa.pppl.gov

If you are using eXodus on a Macintosh for X-windows emulation, read these eXodus tips. MacOS X users can run X-windows applications under X11, much as they would from an X-terminal. Be sure to use -Y when ssh-ing, e.g., in an X11 window (NOT at terminal window):

    ssh -Y myusername@portal.pppl.gov

For PC's running Exceed, read these Exceed tips.

Why, in an xterm session under Mac OS X, does the delete key return the cursor to the beginning of the line instead of deleting the character to the left?

You could control-click in the xterm window and unselect "Backarrow Key BS/DEL" in the popup menu, but you will have to do this for every window. Better to add the following to your .Xdefaults file on the Mac.

    xterm.*backarrowKey: 	false

If you don't know how to edit this file, you can type the following at the command line prompt in an X11 xterm window:

    echo  "xterm.*backarrowKey: false" >> ~/.Xdefaults

If you get an error that the .Xdefaults file does not exist, type:

    echo  "xterm.*backarrowKey: false" > ~/.Xdefaults

(">>" appends to a file, while ">" creates or overwrites an existing file)

Restart your window manager (or exit X11 and restart it), and the Backspace key will delete to the left. If this problem occurs in other X-window applications, like netscape, you may wish to leave off the "xterm." in the command.

How do I program my Logitech 3-button mouse to work in X11 on the Mac?

The middle and right buttons on a Logitech mouse will often function properly WITHOUT installing the Logitech mouse drivers. If you have installed the driver, and the middle and right mouse buttons do not work properly in X windows, bring up the Logitech control panel from System Preferences, and

For the middle button, select the "Advanced_Click" options, and program it to be Option-click.
For the right button, program it to be Right Click.

See http://nstx.pppl.gov/nstx../X11MacOS3ButtonMouse.html.

(if your middle mouse button is not working on your PC, you might look at this site: http://www.digconsys.com/mouse.html and download the "Middle Mouse Button" software.

How can I view my Tektronix plots made in IDL?

Tektronix graphics is an old standard, and you should avoid using it, if possible. For setup, see http://w3.pppl.gov/~pshare/help/xtc.html

On Linux, in an xterm window, assuming you have loaded idl, via, say, "module load nstx/mdsplus"

    IDL> setup_tek,/xtc
    IDL> (plot commands)
    IDL> unsetup_tek

An xtc window will come for you (one per host computer), if it is not there. Bring up the List Box to scroll the plots, send to a file, print, etc.

NOTE THAT VERSATERM HAS BEEN DISCONTINUED AT PPPL as of February, 2006, SINCE TELNET IS CONSIDERED INSECURE!!!

Alternately, from the current version of IDL, you can send Tektronix output to a file and print it, or edit it on your Mac (perhaps read it in VersaTerm and save it as a Pict file?):

    EUROPA$ setup idl tek
    EUROPA$ IDL
    IDL> fileout='IDL_' + screen + '.TEK'
    IDL> device, file=fileout
    IDL> (plot commands)
    IDL> device, /CLOSE

How do I print my plots?

Plots can be printed from Scope. Under the Customize menu, select "Print..." and choose your printer (or a Postscript file for later printing or editing.) Then under the Print menu, select "Print All."

mdsscope.html, mdsplotlist.html, and mdsplot1.html, now have an option for producing Postscript output files (a check box near the Send button).

Plots can be printed from IDL. See setup_ps.pro. Excellent information on Postscript printing is available at the David Fanning web site.

What about making Powerpoint slides?

You can save plots as Postscript files, read them into Adobe Illustrator, and save with a Preview Mode. Then insert these into Powerpoint files. Gif and Jpeg files can also be written from IDL, or saved from output from web tools , and inserted into Powerpoint documents, though these are bit-mapped, and do not look as nice, in general.

Do I have to learn a new editor?

Any editor will do. Read about Nedit on the NSTX-U Software Applications Page.

How do I find out the current shot number?

In IDL:

    IDL> print, lastshot()

From X-windows, you may wish to run the Shotclock .

How do I find out the date of a certain shot?

In IDL:

    IDL> print, mdsshotdate(108880)

I need to use UNIX for something; how do I learn it?

There are many web pages on learning Unix. NSTX-U users may wish to customize their Unix environment -- see $NSTXUSR/util/init_files/AAA_Whats_Here.txt on the PPPL Unix Cluster.

How do I most easily transfer files between UNIX and my Mac?

Connect to server smb://samba1.ppppl.gov/<username> where "<username>" is your Unix username.

How do I easily transfer files between UNIX and my PC?

WinSCP works well (see above), otherwise, probably the easiest way is to:

Right-click on "My Computer" and select "Map Network Drive..."
In the Folder: field, enter \\samba1\<username> where "<username>" is your Unix username.
Click "Finish"

This may only work for your home directory. For other directories, if "SSH Secure File Transfer" is on your PC, you might find it at

    Start...Programs...SSH Secure Shell...Secure File Transfer Client.

This should bring up a two-pane window. Then:

Click on "Quick Connect" on the left in the third row. For "Host Name" enter lark, and your Linux username in "User Name".
Click Connect. If a "Host Identification" window comes up, click "Yes".
Enter you Linux password in the next box.
In the box on the right in the fourth row (with /u/yourusername), type the directory you want to access and hit Enter.
You should be able to drag items from the left window to the right (or the other way). When you double-click a folder in the left pane, another window comes up -- you can drag and drop from that window, as well.

How can I have jobs run automatically on UNIX?

Use the NSTX-U Batch Facility.

What tools are on the PC?

Most things, except CAMAC control. Some diagnostics are based on PCs, typically using PCI-based data acquisition modules. Routines are available to communicate with the MDSplus server for NSTX. See IDLonPC.html for instructions on licensing IDL on PPPL PC's.

How do I get IDL on the PC?

See if the version you want is on our FTP site , or download it from Exelis. See IDLonPC.html.

How do I install IDL on the Mac?

See IDLonMACOSX.html for instructions on installing and licensing IDL on PPPL Mac's.

How do I install MDSplus and jScope on the Mac?

See MDSplusOnMACOSX.html for installing MDSplus, including jScope and jTraverser, on PPPL Mac's.

See jScope_PPPL_Linux.txt for more information on jScope. Here is a local jScope example. jScope has good a Help file.

How do I install MDSplus on the PC?

Download the appropriate version at http://www.mdsplus.org . In the left-hand panel, click on Software and then Downloads, and answer questions. See MDSplus Registry Variables for installing PPPL-specific environmental varables, like paths to data trees.

You will also want to add C:\Program Files\MDSplus\IDL to your IDL_PATH variable, if you will access MDSplus via IDL. (In IDL, go to Preferences...Path).

What tools are on Linux?

Most things, except CAMAC control for the diagnostic highways. We hope to make every thing work on Linux soon.

I'm away from the Lab; what can I do from the Web?

You may use the Web Tools, if you authenticate at the firewall.

For that matter, you may use X-windows if you authenticate, although some people find this rather slow and cumbersome.

What is the difference between the "physics network" and the "engineering network"?

The Engineering Network is behind an additional firewall, so can not be access by default from any lab x-terminal. Control of NSTX-U power supplies, for example, is done from the Engineering Network. The Scientific Network has most diagnostic equipment on it and is more "open." DSO ports in the control room are blue for the Physics Network and red for the Engineering Network.

What is ssh and why should I use it?

It is a Unix program/shell for secure connections (It is also available on most other platforms, such as Mac OSX, Windows XP, and Linux).

Why do I get "X connection to ... broken (explicit kill or server shutdown)"?.

In addition to standard Exceed and ssh problems, this can occur on PCs with Exceed versions 11 & 12. Contact unixadmin for a patch. Quick fixes are to check your disk quota and to "ssh portal" within your xterm window before trying to bring up any other windows.

What is that authentication information? What if I have problems using the SecurID badge?

Read about Authenticating at the PPPL Firewall.

If you have trouble with your SecurID badge, you should visit Lena Scimeca in B160.

Where can I sit in the NSTX-U Control Room?

Some stations are used by "regulars" in the Control Room, and it is best not to commandeer those, unless you ask the normal occupant. Some seats are used less than half the time, and since there are a limited number of seats, those need to be used by less frequent Control Room users and by visiting scientists (as a courtesy, ask people in the area if they know if anyone is using that terminal today). Although not always up-to-date, a typical Control Room seating arrangement is on-line. Seats unlabeled or marked for "Visitor" are open to all, as are seats marked "Programmer."

Naturally, it is better to use a terminal that no one is logged into, but sometimes people forget to log off, so you may need to log them off (if people don't want you to do this, they should leave a note on the terminal).

Ethernet ports in the white DSO boxes should be "alive" if they are not covered by tape. Laptops can be plugged into these ports. If you need another port activated, contact the PPPL Help Desk at x-2275.

Wireless network access is available in the Control Room. See below.

In the future, more stations will be available in the extension control room -- send questions or requirements to Paul Sichta.

Can I use wireless internet access in the NSTX-U Control Room?

Users can sit anywhere they want in the control room and get a wireless connection. Please note the following:

This is a shared network, so users are limited in speed.

The wireless network should be used for limited networking: E-mail, small downloads, internet searches, etc.

The wireless network should not be used for graphics intensive programs like animations, large downloads, or any application where speed is critical. X-window applications may seem a little slow, but are doable.

Anyone planning to connect to the PPPL network from anywhere in the lab should be "netreg-ed." This includes wireless connections. If you are not netreg-ed, stop by the Helpdesk first. This will ensure that proper security features are up-to-date, and resolve any issues that arise during the setup. Without being "netreg-ed" you will only be able to communicate with sites outside the PPPL network.

How do I view pdf, ps (postscript), powerpoint, avi or jpeg files on the Linux cluster?

use gv or ggv for postscript or pdf files.

use ooffice for powerpoint files.

use nautilus for jpeg or png files (but doesn't print). You may also use xv for jpegs.

use mplayer for avi or mpeg files.

How can I fix my miscolored X11 cursor on Intel Macs?

See the IntelMacCursorFix.html

How can I get my buttons colored in IDL widgets like dbaccess?

You have to load the conventionally named X-resources into your ~/.Xresources file:

    xrdb -merge $NSTXUSR/util/init_files/idlcolors.Xresources

This only has to be done once, unless the .Xresources file gets overwritten.

Why can't my IDL session find PPPL .pro routines, like fcplayer.pro ?

Even though you may have done a "module load nstx", your IDL_PATH environmental variable does not point to the area with these files, or perhaps there is a name conflict with something earlier in the path. An IDL startup file, pointed to with the environmental variable IDL_STARTUP may also cause path problems. To see if this is the case, execute the following before getting into IDL:

    source /p/nstxops/util/setup/cleanidl.csh

Why do I get "setenv: Too many arguments" when I source a bunch of shell scripts?

While the following syntax within a .cshrc file, for example, is valid:

    setenv IDL_PATH {$IDL_PATH}:+~/myidl/

Sourcing several files that add to a path can cause the "Too many arguments" error.
Enclosing {$IDL_PATH} in double quotes fixes this error:

    setenv IDL_PATH "{$IDL_PATH}":+~/myidl/

How do I share windows on my Control Room Mac with the NSTX-U Display Wall?

See shareappvnc.html and the vncviewer and SharedAppVnc for the Control Room Macs

From an X-window, you can:
```
    setenv DISPLAY nstxwindowspc:0.0
```
then, any X-window you create from that X-session will be displayed on the Wall.

How do I share windows on my Control Room PC with the NSTX-U Display Wall?

See shareappvnc.html.

From an X-window, you can:
```
    setenv DISPLAY nstxwindowspc:0.0
```
then, any X-window you create from that X-session will be displayed on the Wall.

How do I unzip or un-tar files on my PC?

7-Zip is good.

What computer permissions and environmental variables does a new user need to access NSTX-U data on Linux?

See NSTX_New_User_Setup.