Connecting Vizard and NDI Optotrak

[vserchi]

Hi Jeff, thank you for replying.
I have disabled any firewalls and antivirus as you suggested. I have also checked the IP address I had inserted and if the Optotrak server and the Vizard machine can ping each other. It seems everything is correct in the information I am typing. I am attaching some screenshots about of my cmd window. Can you control if there is anything wrong or weird in what I am doing?
I have tried to add the port information following the IP address. the message error displayed is now different.

import viz
viz.go()

opto = viz.add('optotrak.dle',0,'169.254.187.18 : 139') 
body = opto.getBody(0) 		#first rigid body adding
viz.link(body, viz.MainView)

** ERROR: No data is being sent by Optotrak server at 169.254.187.18 :139
** ERROR: Failed to create extension: optotrak.dle
Traceback (most recent call last):
File "<string>", line 11, in <module>
File "I:\VRproject\Vizard1.py", line 6, in <module>
body = opto.getBody(0) #first rigid body adding
AttributeError: 'VizExtension' object has no attribute 'getBody'

Where do I find the name of the Optotrak server?

Thank you,
Valeria