Knowledge Base

Introduction

This document describes how to achieve automatic synchronization between observational data in The Observer XT and the physiological data acquired with and exported from the BIOPAC MP160 system using BIOPAC's AcqKnowledge 5.0 software.

A large part of this note also applies to AcqKnowledge 4.x.

The versions 4.4 and 5.0 of AcqKnowledge support the import and export of event markers in The Observer XT data format. This means that you can:

• Import AcqKnowledge markers into an observation in The Observer XT.
• Export the events scored in The Observer XT to an AcqKnowledge data file.

Systems Used

The Observer XT

• Processing unit: Dell Precision T5810
• Processor: E5-1620 v3 (Xeon 3.50 GHz 4-core)
• RAM Memory: 8 GB
• Operating system: Windows 10 Professional Edition
• Software: The Observer XT 16, N-Linx Server 1.3

The N-Linx Server can also be installed on a third computer connected to The Observer PC and the BIOPAC PC.

BIOPAC MP160 and AcqKnowledge Software

• Processing unit: Dell Precision T5810
• Processor: E5-1620 v3 (Xeon 3.50 GHz 4-core)
• RAM Memory: 8 GB
• Operating system: Windows 10 Professional Edition
• Software: AcqKnowledge 5.0.2032 with Network Data Transfer Module, N-Linx Agent 1.1.1.0

Notes:

• When you install the N-Linx Agent on the AcqKnowledge computer, you also install a second piece of software, called AcqKnowledge Control.
• You can also install N-Linx Server on a third computer, connected to The Observer XT computer and the AcqKnowledge computer through a local network. Use this configuration when you want to use N-Linx Server to communicate with other applications, independent of The Observer XT.

For Further Information and Help

Other manuals:

• The Observer XT Help
• Quick Start Guide - The Observer XT
• Reference Manual - The N-Linx
• The BIOPAC MP hardware and AcqKnowledge software manuals
• Manuals and user guides on www.biopac.com

For technical support, please contact the Noldus Customer Support Center: https://www.noldus.com/support-center. Browse the customer support database with questions asked by The Observer XT users and answers from the support department.

Automatic Synchronization

After the software is properly installed and configured, automatic synchronization of observational and physiological data is obtained with the following basic steps:

1. Set The Observer XT and AcqKnowledge for DAQ co-acquisition.

   On the AcqKnowledge computer, install the N-Linx Agent communication software, which ensures the files are correctly transferred between computers. In AcqKnowledge, define the channels for data acquisition and one channel for the synchronization signal. In The Observer XT, specify which synchronization signal you want to use (On-Off or Time Code (TCAP)) and the sample rate of the BIOPAC system.

   Connect the Observer XT computer and the BIOPAC system with a synchronization cable.

2. Carry out a Live Observation while The Observer XT sends out the synchronization signal to the BIOPAC system.

   Simultaneously, the BIOPAC AcqKnowledge software acquires data through its modules (e.g., PPG, ECG, GSR).

3. When you stop the observation in The Observer XT, the AcqKnowledge data files are imported automatically into The Observer XT through the local network.

   The data files contain both the physiological data and the time information from the synchronization signal. The observational and physiological data are automatically synchronized.

Notes:

• If you do not have N-Linx installed on the AcqKnowledge computer, you must export the AcqKnowledge data file to an ASCII export file. Make sure to also include header information in this export file.
• Optionally, in The Observer XT you can make a data selection, visualize your data, carry out further data analysis and export the synchronized observational and physiological data. For details, see The Observer XT Help.

Synchronization Cable

Your Observer XT system comes with a synchronization cable. This has the following connectors:

For The Observer XT computer: A 9-pin serial connector. Most modern computers do not have a 9-pin COM port; instead, connect this end to a USB-to-serial adapter, then the USB end to the computer.

For the BIOPAC MP160 system: A mono mini-jack. Connect this end to the input of the INSO isolation adapter. Connect the INISO adapter to analog channel 16 (or any other available channel) on the HLT100C module with the RJ11 cable.

Software Setup

Install N-Linx Server

Important: Install N-Linx Server on the The Observer XT computer, or on a computer connected to both the AcqKnowledge computer and the The Observer XT computer through a local network.

1. Insert The Observer XT installation USB stick in one of the PC's USB ports. Browse to Drivers and Tools\N-Linx Server.
2. Double-click N-Linx Server Setup.exe.
3. Next to Installation type choose Standard, unless you want to specify an installation folder other than the default one (C:\Program Files\Noldus\N-Linx Server).
4. Follow the instructions on your screen.

Install and Connect N-Linx Agent

Important: Install this piece of software on the AcqKnowledge computer.

1. Insert The Observer XT installation USB stick in one of the BIOPAC PC's USB ports. Browse to Drivers and Tools\N-Linx Agent.
2. Double-click N-Linx Agent Setup.exe.
3. Next to Installation type choose Standard, unless you want to specify an installation folder other than the default one (C:\Program Files\Noldus\N-Linx Agent 1).
4. Select Biopac AcqKnowledge control, and click Next.
5. Accept the license agreement, click Install and follow the instructions on your screen.
6. If the N-Linx Agent window does not open after installation, at the bottom-left corner of the screen, on the system tray, click the arrow icon and double-click the N-Linx Agent icon.
7. Next to N-Linx Server Address, enter the IP address of the computer where N-Linx Server is installed. This IP address must be fixed. If The Observer XT and N-Linx Server are installed on the same computer, enter localhost. You can also enter the Computer name instead of the IP address. To find the Computer name of the computer where N-Linx Server is installed, on that computer open the Control Panel and choose System. Locate Computer name.
8. Click Connect. If connection is established, the message at the bottom of the N-Linx window says Connected.

When properly connected, N-Linx Agent shows the connected icon in the system tray.

Set AcqKnowledge for DAQ Co-Acquisition

The aim of this procedure is:

• To allow The Observer XT to gain access to AcqKnowledge. This is done in Networking Preferences in AcqKnowledge.
• To specify the sample rate, the recording channels, and the triggering event (optional) in AcqKnowledge.

Prerequisites:

• AcqKnowledge is running, the experiment is open and the MP160 system is powered up.
• AcqKnowledge must have the licensed Network Data Transfer (NDT) module. If that is not the case, automatic import of AcqKnowledge data into The Observer XT will not work.

Configure Networking Preferences in AcqKnowledge

1. In AcqKnowledge, choose Display > Preferences.
2. Click Networking and select Enable network data transfer.
3. Next to Control TCP port, leave the number as it is. Next, click OK.

Set the Sample Rate in AcqKnowledge

1. Choose MP160 > Set Up Data Acquisition.
2. In the Data Acquisition Settings window, select the Length/Rate tab.
3. Choose the Sample Rate.

Define the Channels for Data Acquisition

1. Click the Channels tab.
2. Select the channels you want to use. You can set up channels automatically by using the Add New Module button to add the modules currently connected to the BIOPAC system. For details, see the AcqKnowledge documentation.
3. Click the View by Modules button. For each module, de-select the option below the green symbol.

Important: If the calibration option is selected, The Observer XT will not be able to start recording using N-Linx, because AcqKnowledge is set to start calibration automatically every time you start acquisition.

If you require auto calibration before acquisition, create a separate graph template with the option selected. Name the template for example "PPG EDA for Calibration". Use that template to do calibration and a short test recording. Then, load the graph template with the option de-selected (named for example "PPG EDA for Acquisition") before starting acquisition from within The Observer XT.

Define the Channel for the Synchronization Signal

1. Click the Channels tab.
2. Select the channel to which you connected the synchronization cable. Click the Analog tab and select the channel to which you connected the synchronization cable. Optionally, rename the Label for this channel to a logical name (for example, Sync signal or Time code signal).
3. For this channel and all channels defined for data acquisition, select the Acquire and Plot check box.

Set The Observer XT for DAQ Co-Acquisition

Connect The Observer XT to N-Linx Server

Follow this procedure just once. The settings are also valid for any new The Observer XT project that you create.

1. In The Observer XT, choose File > Preferences.
2. Click N-Linx Settings on the left.
3. Select Use N-Linx Server to connect with other applications.
4. Next to N-Linx Server address, enter the IP address of the computer with N-Linx Server. Leave the default entry localhost if The Observer XT and N-Linx Server are installed on the same computer. You can also enter the Computer name of the computer where N-Linx Server is installed, instead of its IP address. On the computer where N-Linx Server is installed, open the Control Panel and choose System. Locate Computer name (not Full Computer name).
5. Make sure the N-Linx Server port is 5672. Ask your system administrator for assistance if this port is used by another program.
6. Click Test connection, and check that the message appears Connected. If connection fails, it means that N-Linx Server is not installed properly. Reinstall N-Linx Server, or check that the Windows Firewall is not blocking traffic through port 5672.

Project Setup

Follow these steps for each new The Observer XT project you create to work together with the BIOPAC acquisition system.

1. Open the project and choose Setup > Project Setup.
2. Under Observation Source, select Live Observation.
3. In the Devices window, select DAQ Settings and click the Edit settings button at the bottom-right.
4. In the DAQ Hardware Settings window, select the COM1 port as the Output Device. If there is no COM port available on the The Observer XT computer, use a USB-to-COM converter. The COM port number is randomly assigned by the USB-to-serial converter driver, so make sure to select the active COM port, that is, the one that is Online. For more information, see the documentation of the USB-to-COM device to see which COM port the device uses.
5. Under Signal Type, select Time Code (TCAP), and next to DAQ sample rate, enter the same value as the acquisition sample rate specified in AcqKnowledge. Note that there may be other programs that use COM ports. In that case one or more COM ports in the list are not available. De-install those programs if necessary to free a COM port that can be used by The Observer XT.
6. In the Devices window, check that Biopac AcqKnowledge is selected. If you do not see this item, it is likely that N-Linx Agent is not installed, or Biopac AcqKnowledge Control was not selected when you installed N-Linx Agent.
7. Optional: If more persons are being observed during a single test session, and the BIOPAC system collects data of one of those persons, not the others, it is a good idea to label the data with the subject name. In the Devices window, double-click the item Biopac AcqKnowledge Control and next to Identify device as enter the role of that subject. When imported to The Observer XT, the physiological data sets will be marked with the subject's role.
8. Click OK.

Notes:

• Also use the option Identify device as to specify the subject's role in case you connect multiple BIOPAC systems. Always give unique names. The physiological data streams will be imported with those names.
• You can also specify a template for recording physiological data directly in The Observer XT. In the Devices window, double-click the item Biopac AcqKnowledge Control and under Identify device as select the template you want to use. Make sure that the template corresponds to the channels currently connected to the MP160 system.

Data Acquisition

Carry Out Data Acquisition

1. In The Observer XT, create a new observation (Alt+F6).
2. To start data acquisition, click the Start Observation button.
3. To stop data acquisition, click the Stop Observation button.
4. At the end of acquisition, the physiological data sets are imported automatically. Check that the data sets are listed in the Project Explorer, under External Data Files for the current observation.

Monitoring AcqKnowledge During Acquisition

In the AcqKnowledge program, you can visualize your channels during acquisition. This is useful when you want to check whether the synchronization signal is actually received by the BIOPAC system. Select the Plot check box in the Channels tab of the Data Acquisition Settings window.

Checking N-Linx Agent Status

On the AcqKnowledge computer, you can check the status of N-Linx Agent. Click the arrow icon on the system tray, then double-click the N-Linx Agent icon.

The N-Linx Agent window shows the status of Biopac AcqKnowledge Control and The Observer XT:

• The Observer XT is visible and Online when the program is open.
• Biopac AcqKnowledge Control is Offline when it is installed, but not active. This is the case immediately after installation of N-Linx Agent and after the computer is restarted.
• After creating an observation in The Observer XT, the status of Biopac AcqKnowledge Control becomes Online.
• Online means that Biopac AcqKnowledge Control is started and therefore available for communication. Once Biopac AcqKnowledge Control is started, it remains running until the PC is shut down.

Source: The Observer XT 17 - Technical Note - BIOPAC MP System