Fourier TriLink User manual

User Guide
TriLink™
including
+ MultiLab™for PC & MAC
+ MultiLab™for Pocket PC
+ MultiLab™for Palm
Cut the wire with TriLink wireless
data logging
Integrating student
computing & science

TriLink
User Guide
Fourier Systems
Second Edition
Second print
Printed in May 2005

III
Contents
Introduction ........................................................................................................9
Chapter 1 TriLink .................................................................................. 11
1.1. General....................................................................................... 11
1.1.1. TriLink: System contents ................................................................... 11
1.1.2. External connections......................................................................... 11
1.1.3. Battery ........................................................................................... 12
1.1.4. AC/DC Adaptor ................................................................................ 12
1.1.5. Automatic standby............................................................................ 13
1.1.6. Power saving mode........................................................................... 13
1.2. Stand-Alone Operation .................................................................. 14
1.2.1. Front Panel Layout............................................................................ 14
1.2.2. Working Modes ................................................................................ 14
1. Auto ID .............................................................................................................. 15
2. 8 sensors........................................................................................................... 15
1.2.3. Quick-Start...................................................................................... 15
1.2.4. Load the Last Setup .......................................................................... 16
1.2.5. Internal Clock and Calendar ............................................................... 16
1.2.6. Clear the Memory............................................................................. 16
1.2.7. Choose the Right Setup. .................................................................... 17
1.2.8. Programming Rules and Limitations .................................................... 18
1.3. Sensor Calibration ........................................................................ 19
1.3.1. Hardware Offset Calibration ............................................................... 19
1.3.2. TriLink Automatic Zero Calibration ...................................................... 19
1.3.3. pH Temperature Compensation .......................................................... 20
1.3.4. MultiLab Sensor Calibration................................................................ 20
1.3.5. Factory Calibration (No calibration required)......................................... 20
Chapter 2 Working with Palm Handheld and MultiLab ................................. 21
2.1. Install the Software ...................................................................... 21
2.1.1. System Requirements ....................................................................... 21
2.1.2. Installation ...................................................................................... 21
2.2. Overview..................................................................................... 22
2.2.1. MultiLab for Palm Layout ................................................................... 22
2.2.2. MultiLab for Palm Window Layout........................................................ 22
2.3. Establish wireless communication ................................................... 23
1. Pairing your Palm with a TriLink ........................................................................ 23
2. Renaming TriLink .............................................................................................. 24
3. Changing the password..................................................................................... 25
2.4. Getting Started ............................................................................ 26
2.4.1. Set up a Recording Session................................................................ 26
1. Connect the sensor you want to use ................................................................. 26
2. Open MultiLab application................................................................................. 26
3. Set up TriLink .................................................................................................... 26
4. Select display .................................................................................................... 27
5. Start collecting data........................................................................................... 28
2.4.2. Download Data ................................................................................ 28
2.4.3. Save Data ....................................................................................... 28
2.4.4. Open a File ...................................................................................... 29
2.4.5. Create a New Project ........................................................................ 29
2.5. View the Data .............................................................................. 30
2.5.1. Display Options ................................................................................ 30
2.5.2. Data Map ........................................................................................ 30
2.5.3. Graph view...................................................................................... 30

IV
1. The Cursor ........................................................................................................ 31
2. Zooming ............................................................................................................ 32
3. Scrolling ............................................................................................................ 33
4. Selecting what to display on the X-axis ............................................................. 34
5. Formatting the Graph colors.............................................................................. 34
2.5.4. Table Display ................................................................................... 35
2.5.5. Meter display ................................................................................... 35
1. Meter options..................................................................................................... 35
2. Meter types........................................................................................................ 36
2.5.6. Preview the data .............................................................................. 37
2.6. Analyze the Data .......................................................................... 38
2.6.1. Reading Data Point Coordinates.......................................................... 38
2.6.2. Reading the Difference between two Coordinate Values.......................... 38
2.6.3. Working with the Analysis Tools.......................................................... 38
2.6.4. Analysis tools................................................................................... 39
1. Linear fit ............................................................................................................ 39
2. Derivative .......................................................................................................... 39
3. Integral .............................................................................................................. 39
4. Statistics............................................................................................................ 39
2.7. Export the data ............................................................................ 40
2.7.1. Export to another Palm Handheld device by beaming............................. 40
2.7.2. Export to a desktop computer ............................................................ 40
2.8. Programming TriLink..................................................................... 41
2.8.1. Set up TriLink .................................................................................. 41
2.8.2. Auto detect sensors .......................................................................... 42
2.8.3. Power saving mode........................................................................... 43
2.8.4. Triggering ....................................................................................... 43
2.9. Toolbar buttons............................................................................ 46
2.9.1. Main (upper) toolbar ......................................................................... 46
2.9.2. Graph (lower) toolbar ....................................................................... 46
2.9.3. Meter toolbar ................................................................................... 47
Chapter 3 Working with Pocket PC and MultiLab ........................................ 48
3.1. Install the Software ...................................................................... 48
3.1.1. System Requirements ....................................................................... 48
3.1.2. Installation ...................................................................................... 48
3.2. Overview..................................................................................... 49
3.2.1. MultiLab for Pocket PC Layout ............................................................ 49
3.2.2. MultiLab for Pocket PC Window Layout................................................. 49
3.3. Establishing wireless communication ............................................... 50
1. Pairing your Pocket PC with a TriLink ............................................................... 50
2. Renaming TriLink .............................................................................................. 51
3. Changing the password..................................................................................... 52
3.4. Getting Started ............................................................................ 53
3.4.1. Set up a Recording Session................................................................ 53
3.4.2. Download Data ................................................................................ 55
3.4.3. Save Data ....................................................................................... 56
3.4.4. Open a File ...................................................................................... 56
3.4.5. Create a New Project ........................................................................ 56
3.5. View the Data .............................................................................. 57
3.5.1. Display Options ................................................................................ 57
3.5.2. Data Map ........................................................................................ 57
3.5.3. Graph view...................................................................................... 57
1. The Cursor ........................................................................................................ 58
2. Zooming ............................................................................................................ 59
3. Scrolling ............................................................................................................ 61
4. Selecting what to display on the X-axis ............................................................. 61

V
5. Formatting the Graph colors.............................................................................. 61
6. Change the graph’s units and its number format............................................... 62
3.5.4. Table Display ................................................................................... 62
3.5.5. Meter display ................................................................................... 63
1. Meter options..................................................................................................... 63
2. Meter types........................................................................................................ 63
3.5.6. Preview the data .............................................................................. 64
3.6. Analyze the Data .......................................................................... 65
3.6.1. Reading Data Point Coordinates.......................................................... 65
3.6.2. Reading the Difference between Two Coordinate Values ......................... 65
3.6.3. Working with the Analysis Tools.......................................................... 65
3.6.4. Analysis tools................................................................................... 66
1. Linear fit ............................................................................................................ 66
2. Derivative .......................................................................................................... 66
3. Integral .............................................................................................................. 66
4. Statistics............................................................................................................ 66
3.7. Export the data ............................................................................ 67
3.7.1. Export to another Pocket PC by beaming.............................................. 67
3.7.2. Export to a desktop computer ............................................................ 67
3.8. Programming TriLink..................................................................... 68
3.8.1. Set up TriLink .................................................................................. 68
3.8.2. Auto detect sensors .......................................................................... 69
3.8.3. Power saving mode........................................................................... 70
3.8.4. Triggering ....................................................................................... 70
3.8.5. Calibrate sensors.............................................................................. 72
3.9. Toolbar buttons............................................................................ 73
3.9.1. Main toolbar .................................................................................... 73
3.9.2. Graph toolbar .................................................................................. 73
3.9.3. Meter toolbar ................................................................................... 73
Chapter 4 Working with a desktop computer and MultiLab........................... 74
4.1. Install the Software ...................................................................... 74
4.1.1. System Requirements ....................................................................... 74
1. Windows............................................................................................................ 74
2. Mac OS ............................................................................................................. 74
4.1.2. Installation ...................................................................................... 75
1. Windows............................................................................................................ 75
2. Mac OS ............................................................................................................. 76
4.2. Overview..................................................................................... 77
4.2.1. MultiLab On-screen Layout................................................................. 77
4.2.2. MultiLab Window Layout .................................................................... 77
4.2.3. Working with Projects ....................................................................... 78
4.3. Establishing wireless communication ............................................... 79
1. Pairing your Computer with a TriLink................................................................. 79
2. Renaming TriLink .............................................................................................. 80
3. Changing the password..................................................................................... 81
4.4. Getting Started ............................................................................ 82
4.4.1. Set up a Recording Session................................................................ 82
1. Prepare TriLink.................................................................................................. 82
2. Enable Video Recording.................................................................................... 82
3. Setup the TriLink ............................................................................................... 82
4. Start Recording ................................................................................................. 83
4.4.2. Data recording options ...................................................................... 83
1. Single measurement ......................................................................................... 83
2. Replace ............................................................................................................. 83
3. Add.................................................................................................................... 83
4.4.3. Online Video .................................................................................... 83

VI
1. Online video ...................................................................................................... 83
2. Recording.......................................................................................................... 84
3. Replaying an experiment................................................................................... 84
4. Video and audio Properties ............................................................................... 84
4.4.4. Download Data ................................................................................ 85
4.4.5. Save Data ....................................................................................... 85
4.4.6. Open a File ...................................................................................... 86
4.4.7. Create a New Project ........................................................................ 86
4.4.8. Import data ..................................................................................... 86
4.4.9. Print ............................................................................................... 87
1. Print a graph...................................................................................................... 87
2. Print a table ....................................................................................................... 87
4.5. View the Data .............................................................................. 88
4.5.1. Display Options ................................................................................ 88
4.5.2. Graph Display .................................................................................. 88
1. Split graph view ................................................................................................. 89
2. The Cursor ........................................................................................................ 89
3. Zooming ............................................................................................................ 90
4. Panning ............................................................................................................. 91
5. Edit the Graph ................................................................................................... 91
6. Format the graph............................................................................................... 92
7. Change the graph’s units and its number format............................................... 92
8. Add annotations to the graph ............................................................................ 92
9. Add a graph to the project ................................................................................. 93
4.5.3. The Table Display ............................................................................. 94
1. Editing data values ............................................................................................ 94
2. Editing the table................................................................................................. 94
3. Formatting the table .......................................................................................... 95
4. Add a table to the project .................................................................................. 95
4.5.4. Meters ............................................................................................ 95
4.5.5. Data Map ........................................................................................ 96
1. Control the display with the Data Map ............................................................... 96
2. Understanding Data Map icons ......................................................................... 97
4.5.6. Export Data to Excel ......................................................................... 97
1. Export file settings ............................................................................................. 97
4.5.7. Copy the Graph as a Picture............................................................... 98
4.6. Program TriLink............................................................................ 99
4.6.1. Setup ............................................................................................. 99
1. Quick setup ....................................................................................................... 99
2. Define sensor properties ................................................................................. 100
3. Presetting the display ...................................................................................... 101
4. Preset the graph’s X-axis ................................................................................ 101
5. Power saving mode......................................................................................... 102
6. Triggering ........................................................................................................ 102
4.6.2. Start Recording ...............................................................................104
4.6.3. Stop Recording ...............................................................................104
4.6.4. Clear TriLink’s Memory .....................................................................104
4.6.5. Select TriLink’s operating mode .........................................................104
4.6.6. Calibrating the sensors.....................................................................104
4.6.7. Define a Custom Sensor ...................................................................105
4.6.8. Communication Setup ......................................................................106
4.7. Analyze the data ........................................................................ 107
4.7.1. Reading Data Point Coordinates.........................................................107
4.7.2. Reading the Difference Between two Coordinate Values ........................107
4.7.3. Working with the Analysis Tools.........................................................107
4.7.4. Smoothing .....................................................................................107
4.7.5. Statistics........................................................................................108

VII
4.7.6. Most Common Analysis Functions ......................................................108
1. Linear fit .......................................................................................................... 108
2. Derivative ........................................................................................................ 108
3. Integral ............................................................................................................ 108
4.7.7. The Analysis Wizard.........................................................................109
1. Using the Analysis Wizard............................................................................... 109
2. Curve fit........................................................................................................... 109
3. Averaging ........................................................................................................ 110
4. Functions......................................................................................................... 111
4.7.8. Available Analysis Tools....................................................................111
1. Curve fit........................................................................................................... 111
2. Averaging ........................................................................................................ 112
3. Functions......................................................................................................... 112
4.7.9. Online Analysis ...............................................................................115
4.7.10. Manual Curve Fitting ........................................................................117
4.8. Video Motion Analyzer................................................................. 119
4.8.1. Overview .......................................................................................119
4.8.2. Getting started................................................................................119
1. Video Motion Analyzer basics ......................................................................... 119
2. Saving new movie ........................................................................................... 119
3. Opening a stored movie .................................................................................. 120
4. Saving Video Motion Analyzer project ............................................................. 120
5. Opening Video Motion Analyzer project .......................................................... 120
4.8.3. Capturing new movie .......................................................................120
1. From a device attached to your computer ....................................................... 120
2. From an external source through a video board.............................................. 121
4.8.4. Capturing position and time ..............................................................122
1. Scaling ............................................................................................................ 122
2. Set coordinate system..................................................................................... 122
3. Set step ........................................................................................................... 124
4. Mark the video................................................................................................. 124
5. Changing the colors of the marker and the axes ............................................. 126
4.8.5. Analyzing the data...........................................................................127
4.9. Workbook.................................................................................. 128
4.9.1. Working with Workbook ...................................................................128
4.9.2. Opening a Worksheet.......................................................................128
4.9.3. Create Your Own Worksheet .............................................................129
1. Create an HTML document with Word ............................................................ 129
2. Create a configuration file................................................................................ 129
4.10. Special Tools ............................................................................. 131
4.10.1. Predicting.......................................................................................131
4.10.2. The Timing Wizard...........................................................................131
1. Overview ......................................................................................................... 131
2. Working with the Timing Wizard ...................................................................... 131
3. Measuring methods......................................................................................... 132
4. Time schemes and calculations ...................................................................... 135
5. Tips on using the Timing Wizard ..................................................................... 138
4.10.3. Crop Tool .......................................................................................139
1. To trim all data up to a point............................................................................ 139
2. To trim all data outside a selected range......................................................... 139
4.10.4. Capture Tool...................................................................................139
1. Preparing the capture table ............................................................................. 140
2. Capturing data................................................................................................. 141
3. Displaying the captured data on the graph ...................................................... 141
4.11. Toolbar Buttons.......................................................................... 143

VIII
4.11.1. Main (upper) Toolbar .......................................................................143
4.11.2. Graph Toolbar.................................................................................144
4.11.3. Table Toolbar..................................................................................145
4.11.4. Video Motion Analyzer toolbar ...........................................................145
4.11.5. Capture new movie toolbar ...............................................................145
Chapter 5 Troubleshooting Guide........................................................... 146
5.1.1. TriLink ...........................................................................................146
5.1.2. MultiLab.........................................................................................147
Chapter 6 Specifications....................................................................... 149
Appendix A: Figures ............................................................................... 150
Appendix B: Adding a code resistor to a custom sensor ............................... 151
Index .......................................................................................... 152

Introduction 9
Introduction
TriLinkis the new wireless data logger from Fourier. Based on the MultiLogPRO
design, TriLink has gone one step further by integrating Bluetooth wireless
technology. TriLink is now able to communicate with all types of current and future
PALM, PC, Pocket PC and MAC.
TriLink embodies next generation data logging. Wireless experimentation means
students are no longer tied to their PC. Now free from the clutter of cables their work
and the class computer arrangement can be organized and flexible. No more “wet”
bench tops. Now Science Lab computers can be positioned far away from “wet”
experiments while still logging the experiment and gaining the full benefit of Fourier
data analysis software – cable free!
The TriLink is ideal for classroom mobility and outdoor experimenting. Data can be
turned into graph form, analyzed as well as exported to spreadsheets - all in the palm
of the hand. Based on the MultiLogPRO technologies, the TriLink carries all the same
benefits plus more: wireless communication, 12 bit resolution and 256K sample
memory. The TriLink also works with nearly all of the MultiLog sensors, including
leading sensors from other vendors.
TriLink can record data from up to 8 sensors simultaneously; it is capable of
recording at rates of up to 21,000 samples per second, and of collecting up to
100,000 samples in its internal memory.
TriLink is the ultimate multi-platform data logger, allowing both field and stand alone
operation. TriLink is equipped with a simple keypad and LCD display. TriLink can
connect to PC or MAC and run Fourier's MultiLab analysis software. In addition,
Bluetooth wireless communication link enables TriLink to interface with PDA devices,
such as PALM and Pocket PCs.
A rechargeable battery powers the data logger, which automatically switches to
standby mode 5 minutes after the time of the last data recording, the last button was
pressed, or the last communication was made with the PC. While on standby, TriLink
switches to a low-power state whereby the electronic circuitry and the display are
turned off, using less power.
Combining a handheld computer and the MultiLab for handheld computers software,
TriLink becomes a complete portable sensor based science laboratory that enables
students to collect and visually analyze data.
The TriLink system also comes with the powerful MultiLab for desktop computers
software. When the TriLink is connected to a PC, live displays can be viewed at rates
of up to 100/s, and automatic downloads can be carried out at higher rates. MultiLab
can display the data in graphs, tables or meters, can analyze data with various
mathematical tools, and can show live or recorded video movies of actual
experiments.
The large variety of sensors with which TriLink is compatible makes the unit a true
"digital lab", which can measure scientific phenomena from the fields of Physics,
Chemistry, Biology and Environmental Sciences.
This manual is divided into five sections:
•The first section is dedicated to the data logger itself. Topics include:
Connecting sensors, operation through the data logger buttons, and using
the LCD display to take measurements when working offline.
•The second and third sections explain how to operate the TriLink combined
with Palm or Pocket PC and MultiLab software. Topics include: How to

10 Introduction
establish wireless connection between TriLink and a handheld computer,
how to use MultiLab software to program TriLink, collecting and viewing
data, and copying data to a desktop computer or to other handhelds.
•The forth section gives a comprehensive overview of the MultiLab for
desktop computer software. Topics include: Working online, how to
download data from the data logger to a PC, analyzing the data both
graphically and mathematically, using the MultiLab software to program the
data logger when working online, and working with the video tool.
•The fifth and last section contains hardware specifications and a
comprehensive troubleshooting guide that gives answers to common
questions.

Chapter 1 TriLink 11
Chapter 1
TriLink
1.1. General
1.1.1. TriLink: System contents
1. The TriLink data logger
2. Sensors (see your package list)
3. Four sensor cables
4. USB communication cable
5. Web camera (optional)
6. MultiLab software installation CD.
7. An AC-DC adaptor.
1.1.2. External connections
Figure 1: TriLink external connections

12 Chapter 1 TriLink
1. Sensor input (In) sockets marked In-1/8 In-2/7 In-3/6 and In-4/5: These sockets
are used to connect the sensors. Normally, all four sockets can be used
simultaneously.
To connect a sensor to the TriLink use one of the sensor cables. Plug the
stereo plug into the data logger, and the mini-din plug into the sensor -
arrow facing down.
In order to connect more than 4 sensors at a time, use the splitter cables, which
will enable the connection of up to 8 sensors simultaneously. When a splitter
cable is connected, it must be connected to the socket in the correct numerical
order (e.g. for 5 sensors, connect the splitter cable to In-4/5). One of the two
splitter cables is marked with P1 - that is the main input (the lower input number),
the second line is marked with P2 - indicating that it is the secondary input (the
higher input number). Connect up to four input splitters (DT225) to split the
TriLink’s inputs starting with In-4 (the splitters must be connected in order):
In-4 splits into In-4 and In-5
In-3 splits into In-3 and In-6
In-2 splits into In-2 and In-7
In-1 splits into In-1 and In-8
2. PC USB communication socket: Connect the mini USB plug of the USB
communication cable to the TriLink and the USB Type A plug to the computer’s
USB port (see page 75 for USB driver installation).
3. External DC power supply socket: Plug in an AC/DC 9 - 12V adaptor whenever
you want to save battery power, or to charge the battery when necessary.
Connecting external power to the TriLink automatically charges the internal
battery. The adaptor should meet the required specifications (see section
1.1.4).
1.1.3. Battery
TriLink is equipped with a 2.4V/750mAh NiMH rechargeable battery. Before you start
working with TriLink for the first time, charge the unit for 10 to 12 hours while it is
turned off.
The battery lifetime is about 8 hours of continuous work.
If the data logger’s main battery runs out, the internal 3V Lithium battery backs up
the memory, so no data will be lost.
Note: Battery shelf charge life is about 100 hours. To maximize battery
shelf charge life, always disconnect sensors when not in use.
Disconnect TriLink from the computer when not in use. You can
continue to operate TriLink by plugging it into the wall.
1.1.4. AC/DC Adaptor
•Output: Capacitor filtered 12 VDC, 300mA
•Female plug, center negative

Chapter 1 TriLink 13
1.1.5. Automatic standby
TriLink switches automatically to standby mode after 5 minutes have passed since
the time of the last data recording, the last button was pressed, or the last
communication was made with the PC.
While on standby, TriLink switches to a low-power state where the electronic circuitry
and the display are turned off and TriLink uses less power.
1.1.6. Power saving mode
When performing long experiments at low rates, of up to 1 per minute, TriLink
enables you to work in power saving mode. In this mode TriLink switches to standby
mode and ‘wakes up’for brief periods of time only to execute data logging and then
returns to a standby.
This will enable TriLink to work continuously, without recharging the battery, for up to
100 hours instead of 5 hours in normal mode.
To learn how to operate in power saving mode please refer to:
Section 4.6.1.5 on page 102 if you are working with MultiLab for desktop computers
Section 2.8.3 on page 43 if you are working with MultiLab for Palm Handhelds
Section 3.8.3 on page 70 if you are working with MultiLab for Pocket PC

14 Chapter 1 TriLink
1.2. Stand-Alone Operation
Programming TriLink is done via MultiLab. TriLink will save the setup parameters
until the next time you program it. The keypad allows you to begin and stop data
collection, while the LCD screen displays the recorded values or TriLink's status.
To learn how to set up TriLink please see:
Page 99 if you are working with MultiLab for desktop computers
Page 41 if you are working with MultiLab for Palm Handhelds
Page 68 if you are working with MultiLab for Pocket PC
1.2.1. Front Panel Layout
Figure 2: TriLink front panel
1.2.2. Working Modes
TriLink has two working modes. The default mode is Auto ID and the TriLink is in this
mode when turned on for the first time. When using more than 4 sensors (when using
VERNIER sensors, or if you’ve defined your own sensor), switch to the 8 sensors
mode. You can select the working mode from MultiLab.
TriLink saves the current mode selection and will automatically open in that mode the
next time you turn TriLink on.

Chapter 1 TriLink 15
To learn how to select working mode please see:
Page 104 if you are working with MultiLab for desktop computers
Page 42 if you are working with MultiLab for Palm handhelds
Page 69 if you are working with MultiLab for Pocket PC
1. Auto ID
Automatic sensor identification –just plug in the sensors and the TriLink prepares
itself to collect data from these sensors.
While in this mode you can work with up to 4 sensors simultaneously.
2. 8 sensors
This mode enables data logging from up to 8 sensors simultaneously. Connect up to
four input splitters (DT225) to multiply the TriLink’s inputs starting with In-4 (the
splitters must be connected in order):
In-4 splits into In-4 and In-5
In-3 splits into In-3 and In-6
In-2 splits into In-2 and In-7
In-1 splits into In-1 and In-8
In the splitter cable, one of the two wires is marked with P1 (port 1) - that is the main
input (the lower input number). The second wire is marked with P2 - indicating that it
is the secondary input (the higher input number).
In this mode there is no automatic sensor identification.
Use this mode if you want to work with more than 4 sensors or if you are using
VERNIER sensors.
1.2.3. Quick-Start
Before you first use TriLink, charge the unit for 10 to 12 hours while it is turned off.
1. Turn on TriLink
Press the On/off button. You will see the initialization screen. TriLink performs
brief self-check, loads the last setup you used and momentarily displays its version
number and battery level, then its name and then the display will be changed to show
the current status.
2. Plug in the sensors
Start with the first input on the left (see on page 11). If TriLink is in Auto ID mode (the
default mode) it will identify the sensors you’ve plugged in and display the sensor’s
name.
Note: Sensors must be added successively, starting with input-1. If a
single sensor is used it must be connected to In-1. If two sensors
are used in an experiment, they must be connected to In-1 and In-2.

16 Chapter 1 TriLink
If the TriLink is in 8 Sensors mode you have to select the sensors manually from
MultiLab.
3. Start recording
Press the Run/Stop button to start recording.
TriLink will use the stored setup parameters to collect data (see page 14)
The LCD screen will display:
Logging
At rates of up to 10 samples per second TriLink displays the recorded data values.
You can stop recording any time by pressing the Run/Stop button a second
time. Otherwise logging will stop after the selected number of samples where taken.
The LCD screen will display the number of the experiment in TriLink’s memory:
_ _ _ LOGGER – RUN _ _ _
Log 01 ended
1.2.4. Load the Last Setup
When you turn TriLink on, once the self testing and selection of the input modes has
been completed, it will automatically load the last setup you’ve used.
1.2.5. Internal Clock and Calendar
The internal clock is set the first time you use the Setup command from the MultiLab
software to program the TriLink, and is automatically updated to the PC’s time and
date each time you connect your TriLink to a PC.
The internal clock and calendar is kept updated even when the TriLink is turned off,
but it will be erased if the 2.4V battery is dead. It will be updated the next time TriLink
will be connected to a computer or a Palm.
1.2.6. Clear the Memory
TriLink automatically checks the available memory before it begins the recording. If
there is not enough memory you will see this message on the display:
_ _ _ LOGGER-RUN _ _ _
Clear = (Run)
Press the Run/Stop button to clear the memory and begin recording.

Chapter 1 TriLink 17
1.2.7. Choose the Right Setup.
1.Sampling rate
The sampling rate should be determined by the frequency of the phenomenon being
sampled. If the phenomenon is periodic, sample at a rate of at least twice the
expected frequency. For example, sound recordings should be sampled at the
highest sampling rate –20,800/sec, but changes in room temperature can be
measured at slower rates such as once per second or even slower, depending on the
speed of the expected changes. THERE IS NO SUCH THING AS OVER-
SAMPLING. For extremely smooth graphs, the sampling rate should be about 20
times the expected frequency.
Note: Sampling at a rate slower than the expected rate can cause
"frequency aliasing". In such a case, the graph will show a
frequency much lower than expected. In Figure 3 below, the higher
frequency sine wave was sampled at 1/3 of its frequency.
Connecting the sampled points yielded a graph with a lower,
incorrect frequency.
Figure 3: Frequency Aliasing
2.Sampling points
After you have chosen the sampling rate, choosing the number of points will
determine the logging period: Samples / Rate = Logging time. You can also choose
the duration of an experiment first, and then calculate the number of samples:
Samples = Logging time ×Rate.
Continuous
In the Continuous mode, TriLink does not save data, and can continue logging
indefinitely.
If TriLink is connected to the PC and the MultiLab software is running, the data is
automatically transferred to the computer and displayed in a real time graph.
To operate in Continuous mode select RATE equal to or less than 100/s and
SAMPLES =Continuous.

18 Chapter 1 TriLink
1.2.8. Programming Rules and Limitations
The following are some rules and limitations you must take into account when
programming the TriLink, as TriLink integrates all programming limitations
automatically. TriLink will only allow the programming of settings that comply with the
rules below.
1.Sampling points:
•Increasing the number of active inputs limits the number of
sampling points one can choose. The following condition must
be always satisfied: Samples ×Active Inputs < Memory.
•TriLink’s memory is sufficient for 170,000 samples.
•When sampling at rates faster than 100 samples per second the
memory can store only four experiments of 32,000 samples
each.
•When sampling at rates of 100 samples per second or less,
selecting Maximum sampling points will create up to four
successive files of 42,500 points each (a total of 170,000
points), depending on the available memory.
2. Sampling rate:
The number of sensors in use limits the maximum sampling rate:
Number of sensors Maximum sampling rate Resolution
1 sensor 20,800 samples per second 10 bit
1 sensor 11,200 samples per second 12 bit
2 sensors 3,400 samples per second 12 bit
3 sensors 2,500 samples per second 12 bit
4 sensors 1,900 samples per second 12 bit
5 sensors 1,600 samples per second 12 bit
6 sensors 1,400 samples per second 12 bit
7 sensors 1,200 samples per second 12 bit
8 sensors 1,050 samples per second 12 bit
3. Continuous sampling
•Continuous sampling is possible up to a maximum sampling rate of
100/s.

Chapter 1 TriLink 19
1.3. Sensor Calibration
In this chapter you will learn how to increase the TriLink system accuracy using
calibration. Most of the sensors are linear, i.e. the output level of each sensor
changes according to the equation:
baXY +=
Where:
Y–The sensor’s output (voltage level varying from 0 to 5V)
X–The sensor’s input
a–The sensor’s gain
b–The sensor’s offset
The calibration process allows us to control the offset, and in some cases even the
gain, of a sensor. The TriLink system offers 4 types of calibration:
1. Hardware offset calibration.
2. TriLink automatic zero calibration.
3. MultiLab “Sensor calibration”.
4. Factory calibration (no manual calibration required).
1.3.1. Hardware Offset Calibration
On some of the sensors there is a screw controlling the sensor offset. To calibrate
the sensor, rotate this screw until the sensor shows the correct measured value
(obtain the actual "correct value" from another source that is known to be accurate).
1.3.2. TriLink Automatic Zero Calibration
TriLink is able to automatically calibrate the sensor offset for all analog sensors
accurately, quickly, and for every new experiment conducted.
The calibration method is very simple. Whenever you plug in a sensor, the data
logger checks to see if the selected sensor measures a value within ±2% of its “zero
value”. If so, TriLink sets that value as zero.
1) To enable this feature, make sure that the sensors are at their “zero values”
when you plug them in. To ensure the most accurate “zero value”: Shorten the
Voltage sensor plugs.
2) Leave the Current sensor plugs open.
3) Cover the Light, Photo-Gate, and Microphone sensors.
4) Insert the pH sensor in a pH-7.0 solution.
5) Unload the Force Transducer.
6) Place the Accelerometer on a stationary surface.
7) Place the Temperature probes in ice water.
8) Place the Pressure sensor in a 1 ATM (1013 mb) Chamber.