Using VNC to View Antelope Real-time Display

Command Line Startup Method for PEPP schools

The following steps need to be followed to run the antelope real-time display software for the PEPP network.  It assumes the computer your are using has a connection to the internet and that you have already installed the VNC software on it.  (See installing VNC instructions )

Step 1:  Request an account.
Access to the real-time display is currently available only to registered users.  All PEPP schools are welcome to use this service, but you will need to request an account if you don't already have one.  Send an email to giving your name, school, and preferred email address.  The sysadmin will set up your account and send you a return email giving the account name and account password.

Step 2:  Verify login and start the VNC server.
We use the VNC program from ATT to connect to our antelope system because it is machine dependent and has proven to be easy to install on all common platforms.  It uses a client server arrangement (for more information on VNC consult the documentation found at  VNC documentation ) which means that you will need to set up a "server" on our end (the machine and run "client" on your end.   Both must be present for all this to work, but the server must be started first.  To do this you will need to connect to our machine (  There are numerous options for this.  The most widely available methods are some form of telnet access either through a special application (e.g. at IU a package from Hummingbird Communications Inc. is commonly used by students) or through a web browser.  For newcomers we recommend you start with your web browser as it is the simplest approach, but if you are already familiar with another communication package feel free to use it.  All you need to do is simply type the following into the "Go to:" entry used for manually typing a web address:  telnet://  (If you want to try this RIGHT NOW just click this link:   Connect NOW to aesn )  You should get a new window that looks like this:

Once you have logged into aesn and gotten a command prompt from telnet you need to start the vncserver.  To do this just type:


The first time you type this you will be asked to enter a password.  For security reasons we recommend strongly this be DIFFERENT from the login password you just used.  You should probably write the password you chose down somewhere as these things are easy to forget.

An odd feature of the vncserver setup is that it does not actually start the vncserver on this first entry where you enter the password.  Consequently, you will need to type this command again.  However, we suggest that after you set the password on the first run that subsequent vncserver runs be started as follows:

vncserver -alwaysshared -dontdisconnect

The -alwaysshared and -dontdisconnect allow multiple people to simultaneously access the same display.  In this way, for example, you could have an entire classroom of computers access the display simultaneously.  They would, however, be fighting each other for changes in the display.

This time you should get output something like this: vncserver -alwaysshared -dontdisconnect

New 'X' desktop is

Starting applications specified in /export/d0/home/pavlis/.vnc/xstartup
Log file is /export/d0/home/pavlis/.vnc/

It is IMPORTANT to note the display name that vncserver tells you here because you will need this in a moment.  For the example above it is:   Normally it also a good idea to look at the output of the log file to make sure the server started correctly.  Here is what I did to check this for the above example: cat .vnc/
24/02/00 08:51:17 Xvnc version 3.3.3
24/02/00 08:51:17 Copyright (C) 1999 AT&T Laboratories Cambridge.
24/02/00 08:51:17 All Rights Reserved.
24/02/00 08:51:17 See for information on VNC
24/02/00 08:51:17 Desktop name 'X' (
24/02/00 08:51:17 Protocol version supported 3.3
24/02/00 08:51:17 Listening for VNC connections on TCP port 5901
24/02/00 08:51:17 Listening for HTTP connections on TCP port 5801
24/02/00 08:51:17   URL
Can't find include file /export/d0/home/pavlis/.Xresources

If you get something significantly different from this, it means something probably went wrong.  The most likely error is a typo on one of the arguments (i.e. -alwaysshared -dontdisconnect), but there are lots of ways this can break.  If you get a mysterious message, first check ATT's documentation VNC documentation ) and if you can't figure it out send email to us and we'll try help you sort out the problem.

There are a series of more advanced problems/issues you will need to be aware of if you find you want to really use this stuff.   If you are a beginner, just continue on, but eventually we suggest you look at the page  VNC usage suggestions.

You should also eventually read the following page on  VNC security and PEPP.
Step 3:  Start VNC client and connect.
If you have created a shortcut on the desktop for vncviewer, just double click the icon.  In Windows if you did a full install of the vnc software you can also start the viewer from the Windows "Start" button by following:  Start->Programs->Vnc->Run VNCviewer

All small window will pop up asking for the name of the "VNC server".  This is where you need what noted above.  For the above example, I would enter into the typein box:   If you get this right, you will get a new small box to enter the password.  Type that in.  If you get that right, a larger window will appear that looks something like the following:

Please note the following instructions will likely soon become superseded by a simpler procedure.  A simpler graphical user interface is currently under construction that will remove the need for the command-based method of launching described here.


Step 4:  Launching antelope applications.

If you know UNIX you have a lot of options here as the command window you will see in the VNC window is a standard unix shell.  However, before you start you will need to first enter the following command in the window labeled "X Desktop":

setenv DISPLAY

where you will probably have to change the ":3" to a number defined for the display number the vncserver assigned you (see above).  (Note:  we are working on a way to remove the burden of typing this obscure command, but for now you have to do it this way.)

Now you can simply type one of the following commands that are  currently defined for your account:

display_pepp   Typing this command will bring up an antelope real-time display of PEPP stations currently on the network and targeting our server.

display_anza   Typing this command will bring up an antelope real-time display for stations of the ANZA network in southern California.

pepp_events    Typing this command brings up a map display showing a series of maps of preliminary epicenter locations determined from PEPP stations.  At the moment the map displays are focused on Indiana, but national and global scale maps are also available by cycling through the list of available maps (Use the "Next Map" button on the display).

anza_events    Similar display for the anza network.

For further information on the real time display program see  orbmonrtd man page .

For more information on the mapping program see  dbevents man page

Step 5:  Exiting the VNC viewer

To exit the vncviewer just move the mouse pointer to the tiny icon in the upper left corner of the vncviewer window and click the left mouse button.  Select Quit