Previous Next        Current Page: NeXtMidas User's Guide / Third-Party Compatibility / VNC
Release Information   
Getting Help   
Basic Concepts   
Result Parameters   
XML Support   
System Operation   
Java WebStart   
X-Midas Interoperability   
Third-Party Compatibility   
   - Apache   
   + Web Browsers   
   + WebStart   
   - Profilers   
   - NetBeans   
   - Eclipse   
   - JBuilder   
   - Intel Fortran Compiler   
   - Portland Group Compiler   
   - SWIG   
   - VNC   
Installation and Customization   
Running NeXtMidas Independently   
Timelines - Keywords, Updating, Known Issues   
Installing and Using Docker   

Using VNC with NeXtMidas

Virtual Network Computing (VNC) is a graphical desktop sharing system which uses the RFB protocol to remotely control another computer. It transmits the keyboard and mouse events from one computer to another, relaying the graphical screen updates back in the other direction, over a network.

A VNC session is generally composed of a VNC Server and a VNC Viewer (or Client). For the purposes of this demonstration we will use software available on a standard workstation installation of Redhat Enterprise Linux ES release 4.

  1. VNC Server
  2. VNC Viewer

VNC Server

It has been noted by users that NeXtMidas will not function in a VNC session if the vncserver -depth option is set to 32.

The VNC Server is started on the machine that will be running the NeXtMidas application. It is also commonly referred to as the "remote" machine.

To start the VNC Server session execute:

vncserver -geometry widthxheight -depth depth :display#


[user@remotesystem ~]$ vncserver -geometry 1280x1024 -depth 24 :1

New 'remotesystem:1 (user)' desktop is remotesystem:1

Starting applications specified in /home/user/.vnc/xstartup
Log file is /home/user/.vnc/remotesystem:1.log

[user@remotesystem ~]$

We have provided a description of the command line arguments used above. Please see the vncserver man page for a full listing of options.

  • -geometry widthxheight
    Specify the size of the desktop to be created. Default is 1024x768.
  • -depth depth
    Specify the pixel depth in bits of the desktop to be created.
    Default is 16, other possible values are 8, 15 and 24 - anything else is likely to cause strange behaviour by applications.
  • :display#
    Specify the display number to use for VNC session displays. Default is :1.

To stop the VNC Server session execute:

vncserver -kill :display#

Example: [user@remotesystem ~]$ vncserver -kill :1
Killing Xvnc process ID 26966
[user@remotesystem ~]$

Please see the man pages for vncserver to see a full listing of available options

The first time that you run vncserver you will be prompted for a password. This password will by used when trying to establish a VNC Viewer session.

Back to Top

VNC Viewer/Client

The VNC Viewer is started on the machine that will be receiving the VNC windows. It is commmonly referred to as the "local" machine.

To start the VNC Viewer session execute:

vncviewer host:display


[user@remotesystem ~]$ vncviewer

VNC Viewer for X version 4.0b4 - built Jan 8 2007 11:53:03
Copyright (C) 2002-2003 RealVNC Ltd.
See for information on VNC.

Mon Jul 7 14:45:35 2008
CConn: connected to host port 5901
CConnection: Server supports RFB protocol version 3.8
CConnection: Using RFB protocol version 3.7

A VNC Authentication dialog box will open. Insert the password that was used to initialize the VNC Server.

Once the proper password has been entered the VNC Viewer window will open.

Click on the X in the top right corner to close the VNC Viewer.

Back to Top