Watching Intersense Targets

Sometimes, you will want to see how the Intersense is tracking while Previzion is still running.  To see if the Intersense is still tracking, you can actually bring up ISDemo32 while Previzion is on and connected to the Intersense. Since sfServer is already running, ISDemo will connect to sfServer. You can then open Tools->Optical Data Display and display the current tracking state while running Previzion.

Warning — the real time display of the tracking targets in ISDemo32 is intensive on the system, and will cause Previzion to drop frames, so we don’t usually recommend it. It’s useful in the verification and testing stage, however.

To lower the impact on the system, you can shrink the window until it is down to about 2″ x 2″; this lets the system operate more normally. When doing real shots, however, the tracking display should be turned off.

You may also notice a weird rendering artifact (a small dark square) in the Previzion video display after running ISDemo32; that’s due to how ISDemo32 renders into the framebuffers. It doesn’t affect the output signal, but if you don’t want it to be there just move over the Previzion screen so that the ISDemo 32 screen does not overlap it.

Windows 7 and Watching Targets

The Windows 7 builds of sfServer can only support 1 TCP/IP connection at a time. This is a problem, as by default both Previzion and ISDemo use the TCP/IP connection protocol. Under Windows 7, if you connect to sfServer with ISDemo while a session of Previzion is running, the Previzion session will be disconnected and will not receive updated tracking information.

Setting Previzion Connection to UDP

To correct this, it is possible to set Previzion to connect to sfServer over UDP. Warning: the UDP data stream is read-only, so this means that users cannot set the Pitch and Yaw angles of the Intersense from inside Previzion. Instead, the Pitch and Yaw angles must be set using the ISDemo interface.

This modification is recommended only for users that truly need the ability to monitor target recognition in real time.

To set Previzion to connect over UDP:

  • Create a file called isports.ini in the /Previzion main directory. The contents should be:


  • While sfServer is running, open ISDemo and choose Tools->Command String. Enter:


and press Enter.

  • Save settings with File->Save Current Settings.
  • Exit ISDemo, sfServer, and Previzion. Restart Previzion, which should now bring up sfServer and connect normally.

You will notice that changing the Pitch and Roll values in the Previzion Airtrack/Intersense Configure interface no longer affects the data from the IS1200. These must now be set within ISDemo.

In addition, the orientation of the wireframe drawing of the IS1200 in Previzion’s Observer View will no longer correspond to the actual setting set within ISDemo.


Setting Pitch Angle Manually in ISDemo

  • Start ISDemo, connect to the IS1200, and select Parameters->Station and Sensor Parameters.
  • Make sure station 1 is selected, then click Change.
  • Input the desired pitch into the highlighted Pitch line , then select Command->Exit.
  • Exit the Station Configuration window to get back to the main ISDemo window.
  • Select File->Save Current Setting to save the pitch value.

Reverting to TCP/IP

  • In ISDemo, select Tools->Command String and enter: MEthUdp0 and press Enter.
  • Select File->Save Current Settings.
  • Change the isports.ini file in /Previzion to


  • Restart Previzion. When Previzion starts up sfServer, it should now be in TCP/IP mode.