Knowledge Base

Introduction

What Is N-Linx?

N-Linx is a network communication protocol that is developed for Noldus software. At present it is used to control an application with The Observer XT and to transfer data from the application to The Observer XT. As an example, N-Linx is used to start and stop video recording with MediaRecorder by starting and stopping an observation in The Observer XT. Also, N-Linx is used to start and stop FaceReader analysis with an observation in The Observer XT and to transfer FaceReader analysis data and independent variables to The Observer XT.

Components

N-Linx communication is done by two components: N-Linx Server and N-Linx Agent.

N-Linx Server receives information from one application and sends it to another one.

N-Linx Agent starts the application when it is not already running and forwards commands from N-Linx Server to the application.

Connections

The Observer XT and N-Linx Server can be installed on any computer in the network. N-Linx Agent and Application 2 must be installed on the same computer. The following describes the data streams in an N-Linx setup:

1. The Observer XT sends a command to N-Linx Server.
2. N-Linx Server forwards the command to N-Linx Agent, or directly to Application 2.
3. N-Linx Agent starts Application 2, if it is not already open. It also sends commands to Application 2, for example Start Data Acquisition, or Start Video Recording.
4. Application 2 sends its data to N-Linx Server.
5. N-Linx Server forwards the data to The Observer XT.

Which Applications Work with N-Linx?

At present the following setups are supported:

• The Observer XT with MediaRecorder
• The Observer XT with FaceReader
• The Observer XT with Viso
• The Observer XT with BIOPAC AcqKnowledge
• The Observer XT with Tobii Pro Studio and Tobii Pro Lab

The Observer XT with MediaRecorder

Version numbers:

• The Observer XT 13 or higher
• MediaRecorder 4 or higher

The following is obtained:

• When you create a new Observation, MediaRecorder starts and loads a configuration.
• When you start an Observation, MediaRecorder starts recording.
• When you stop an Observation, MediaRecorder stops recording.
• The recorded videos are automatically linked to the observation in The Observer XT and synchronized with the events.

See Media Recorder with The Observer XT in the Media Recorder Help for details.

The Observer XT with FaceReader

This setup works without N-Linx Agent.

Version numbers:

• The Observer XT 14.0 or higher
• FaceReader 7.0 or higher

The following is obtained:

• When you create an observation in The Observer XT, FaceReader creates a participant with a camera analysis.
• When you start an observation in The Observer XT, FaceReader starts analyzing.
• When you stop an observation in The Observer XT, FaceReader analysis stops.
• The FaceReader data are imported into the observation of The Observer XT.
• The FaceReader data are synchronized with the Event Log.
• The FaceReader independent variables are imported into the Independent Variables list of The Observer XT.
• FaceReader videos are imported into the observation of The Observer XT and synchronized with the data (with The Observer XT 14.1 or higher and FaceReader 7.1 or higher).

See FaceReader with The Observer XT in The FaceReader Help for details.

The Observer XT with Viso

Version numbers:

• The Observer XT 12.5 or higher
• Viso 2 or higher

The following is obtained:

• Viso Sessions can be imported directly from Viso, without exporting them as .odx files first.

The Observer XT with BIOPAC AcqKnowledge

Version numbers:

• The Observer XT 14.1 or higher
• BIOPAC AcqKnowledge 5.0.2032 or higher

The following is obtained:

• When you start an observation, AcqKnowledge starts physiological data acquisition.
• When you stop an observation, AcqKnowledge stops physiological data acquisition.
• The physiological data are imported into the observation of The Observer XT and synchronized with the events.

See the Technical Note - BIOPAC MP System - The Observer XT for details. You can find this technical note on The Observer XT installation USB stick or download it from the Noldus website.

The Observer XT with Tobii Pro Studio and Tobii Pro Lab

Version numbers:

• The Observer XT 14.1 or higher
• Tobii Pro Studio 3.4.7
• Tobii Pro Lab 1.98

The following is obtained:

• When you start an observation, eye tracking starts.
• When you stop an observation, eye tracking stops.

See the Technical Note - Tobii Pro Eye Trackers - The Observer XT for details. You can find this technical note on The Observer XT installation USB stick or download it from the Noldus website.

Using Your Own Application with N-Linx

Noldus IT offers two N-Linx SDKs to build your own setup with a Noldus application, for example to start your application when The Observer XT starts an observation. An SDK is available for application Start and Stop and an SDK for Event and continuous data. Contact your Noldus sales representative for the possibilities.

Support

If you have any problems, questions, remarks or comments, please contact us through the Noldus website and fill out a Support Request Form (preferred) or phone us during normal working hours. Contact details are available at the support section of the Noldus website.