Coherent PowerMax-USB, PowerMax-RS User manual
User Manual
PowerMax™-USB/RS
Sensor System
User Manual
PowerMax-USB/RS
Sensor System
27650 SW 95th Ave.
Wilsonville, OR 97070
PowerMax-USB/RS User Manual
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is accurate. The information, figures, tables, specifications and schematics
contained herein are subject to change without notice. Coherent makes no
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special, incidental or consequential damages resulting from any defects in
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Technical Support
In the U.S.:
Should you experience difficulties with your product, or need technical
information, please visit our website: www.Coherent.com
additional support by either telephoning our Technical Support Hotline at
1.800.343.4912, or e-mailing our Support Team at
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If you call outside our office hours, your call will be taken by our answering
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If there are technical difficulties with your product that cannot be resolved
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Outside the U.S.:
If you are located outside the U.S., visit our website for technical
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phone numbers and addresses can be found on the Coherent website,
www.Coherent.com
.
. You can obtain
Coherent provides web and telephone technical assistance as a service to
its customers and assumes no liability thereby for any injury or damage
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ii
Table of Contents
TABLE OF CONTENTS
Preface ................................................................................................................................. vii
RoHS Compliance ............................................................................................................... vii
U.S. Export Control Laws Compliance ............................................................................... vii
Publication Updates .............................................................................................................vii
Symbols Used in This Document ........................................................................................ vii
Safety ...........................................................................................................................................1
Waste Electrical and Electronic Equipment (WEEE, 2002)...................................................1
Declaration of Conformity......................................................................................................2
Description ...............................................................................................................................3
Introduction.............................................................................................................................3
Product Overview ...................................................................................................................3
Product Features ............................................................................................................3
Software Features ..........................................................................................................4
Technical Description .............................................................................................................5
Thermopile Technology .................................................................................................5
Long-Pulse Energy Measurement With a Thermopile .........................................6
Semiconductor Technology ...........................................................................................7
Applying Wavelength Compensation Accuracy.....................................................................9
Operation................................................................................................................................11
LED Status Indicators...........................................................................................................11
PowerMax-USB LED Lights.......................................................................................11
PowerMax-RS LED Lights..........................................................................................12
Powering PowerMax-RS Sensors.........................................................................................12
Extending Cable Length .......................................................................................................12
How to Take a Power Measurement .....................................................................................13
Measuring Power With a PowerMax-USB Thermopile Sensor ..................................13
Measuring Power With a PowerMax-RS Thermopile Sensor .....................................16
Zeroing..................................................................................................................................18
Setting the Wavelength .........................................................................................................18
Using the Software................................................................................................................19
Front Panel...................................................................................................................19
Keyboard Shortcuts.............................................................................................19
Select Sensor.......................................................................................................20
Start/Stop Data Collection ..................................................................................21
Trending Chart....................................................................................................22
Histogram Chart..................................................................................................23
Tuning Chart .......................................................................................................24
Alignment Target Chart ......................................................................................25
Synchronized Trending Chart.............................................................................26
Reset Error ..........................................................................................................28
Graph Palette.......................................................................................................29
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PowerMax-USB/RS User Manual
Live Reading.......................................................................................................30
Wavelength .........................................................................................................30
Live Data Averaging ...........................................................................................31
Mean ...................................................................................................................31
Min......................................................................................................................32
Counts .................................................................................................................32
Std Dev................................................................................................................33
Max .....................................................................................................................34
Mode ...................................................................................................................34
Sample Collection...............................................................................................35
Sample Size.........................................................................................................35
Zero Sensor .........................................................................................................36
Reset Button........................................................................................................36
Gain Correction...................................................................................................37
Collection Mode .................................................................................................38
Collection Interval ..............................................................................................38
Log Data to File ..................................................................................................39
Log Data File ......................................................................................................39
Menus...........................................................................................................................40
File Menu............................................................................................................40
Settings Menu .....................................................................................................45
View Menu..........................................................................................................47
Window Menu.....................................................................................................49
Help Menu ..........................................................................................................49
Host Interface.......................................................................................................................51
Introduction...........................................................................................................................51
Message Terminators ............................................................................................................52
Messages Received by the Sensor ...............................................................................52
Messages Sent by the Sensor .......................................................................................52
Host Command Quick Reference .........................................................................................53
SCPI Interface Section..........................................................................................................55
Syntax and Notation Conventions ...............................................................................55
Commands and Queries ...............................................................................................56
SCPI Common Commands.................................................................................56
System Options ...................................................................................................56
Error Record Reporting and Collection ..............................................................58
Measurement Setup and Control.........................................................................60
Querying Measurement Data ..............................................................................62
Sensor Information .............................................................................................63
Legacy LaserPAD/SSIM Interface Section...........................................................................65
Commands and Queries ...............................................................................................65
LaserPAD/SSIM Streaming Data Record Format .......................................................69
Data Streaming Transmission Interface Section ...................................................................70
Streaming Measurement Data......................................................................................70
Commands and Queries ...............................................................................................70
Operational Parameters.........................................................................................................71
iv
Table of Contents
Calibration and Warranty ...........................................................................................73
Calibration ............................................................................................................................73
Coherent Calibration Facilities and Capabilities ..................................................................73
Limited Warranty ..................................................................................................................74
Extended Warranty................................................................................................................74
Warranty Limitations ............................................................................................................75
Obtaining Service .................................................................................................................75
Product Shipping Instructions...............................................................................................76
Appendix A: Specifications..........................................................................................77
Compatible Sensors ..............................................................................................................77
Appendix B: Troubleshooting and Error Messages.....................................79
Index ..........................................................................................................................................81
LIST OF TABLES
1. Wavelength Compensation Accuracy ................................................................................10
2. PowerMax-USB LED Light Conditions............................................................................11
3. PowerMax-RS LED Light Conditions...............................................................................12
4. Keyboard Shortcuts............................................................................................................19
5. Host Command Quick Reference ......................................................................................53
6. Status Condition Character Definitions .............................................................................56
7. Error Codes and Description Strings .................................................................................58
8. Measurement Data Record Formats ..................................................................................62
9. Flags Character Definitions ...............................................................................................63
10. Measurement Data Record Formats ..................................................................................69
11. Data Streaming Transmission Rates ..................................................................................71
12. Operational Parameters......................................................................................................71
13. Coherent Service Centers...................................................................................................76
14. Compatible Sensors ...........................................................................................................77
LIST OF FIGURES
1. Waste Electrical and Electronic Equipment Label...............................................................1
2. Saturation Power and Minimum Power for PowerMax-USB UV/VIS Quantum Sensor ...8
3. Photo Sensitivity Temperature Characteristics ....................................................................9
4. RV Spectral Correction for Thermal Sensors (Normalized to Calibration Wavelength)...10
5. Front Panel.........................................................................................................................19
6. Drop-Down Menus ............................................................................................................40
7. File Menu...........................................................................................................................40
8. Settings Menu ....................................................................................................................45
9. View Menu.........................................................................................................................47
10. Window Menu....................................................................................................................49
11. Help Menu .........................................................................................................................49
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PowerMax-USB/RS User Manual
vi
Preface
Preface
RoHS Compliance
U.S. Export Control Laws Compliance
This manual contains user information for the Coherent
PowerMax™ meterless power sensors and the PowerMax PC software.
This Coherent product is RoHS compliant.
It is the policy of Coherent to comply strictly with U.S. export
control laws.
Export and re-export of lasers manufactured by Coherent are subject
to U.S. Export Administration Regulations, which are administered
by the Commerce Department. In addition, shipments of certain
components are regulated by the State Department under the International Traffic in Arms Regulations.
The applicable restrictions vary depending on the specific product
involved and its destination. In some cases, U.S. law requires that
U.S. Government approval be obtained prior to resale, export or
re-export of certain articles. When there is uncertainty about the
obligations imposed by U.S. law, clarification should be obtained
from Coherent or an appropriate U.S. Government agency.
Publication Updates
Symbols Used in This Document
To view information that may have been added or changed since this
publication went to print, connect to www.Coherent.com.
This symbol is intended to alert the operator to the presence of
dangerous voltages associated with the product that may be of
sufficient magnitude to constitute a risk of electrical shock.
This symbol is intended to alert the operator to the presence of
important operating and maintenance instructions.
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PowerMax-USB/RS User Manual
viii
Safety
SAFETY
Carefully review the following safety information to avoid personal
injury and to prevent damage to this product or any equipment
connected to it. There are no user-serviceable parts in Coherent
PowerMax meterless power sensors. For service information, refer
to “Obtaining Service” on page 75.
Do not operate the system if its panels are removed or any of the
interior circuitry is exposed.
Waste Electrical and Electronic Equipment (WEEE, 2002)
Do not operate the system in wet or damp conditions, or in an
explosive atmosphere.
Do not operate the system if there are suspected failures. Refer
damaged units to qualified Coherent service personnel.
The European Waste Electrical and Electronic Equipment (WEEE)
Directive (2002/96/EC) is represented by a crossed-out garbage
container label (Figure 1). The purpose of this directive is to minimize the disposal of WEEE as unsorted municipal waste and to facilitate its separate collection.
Figure 1. Waste Electrical and Electronic Equipment Label
1
PowerMax-USB/RS User Manual
Declaration of Conformity
2
DESCRIPTION
Description
Introduction
Coherent PowerMax-USB and PowerMax-RS sensors are the
world’s first laser power sensors that utilizes state of the art microelectronics miniaturization techniques and integrate an entire instrument within a USB 2.0 or RS-232 cable connector. Specifically,
PowerMax-USB and PowerMax-RS sensors have all the signal
processing and power measurement electronics normally contained
in a LabMax meter and connect directly to a PC with plug-and-play
functionality. Ideally suited for low- and high-volume embedded
sensor applications, Coherent’s new family of sensors eliminates the
need for a separate meter box, thus delivering a significant savings
in cost and space, but with no reduction whatsoever in performance.
This measurement platform can also be used to measure the energy
in a long laser pulse—typically greater than 1 millisecond in pulse
width—by integrating the output of a thermopile sensor.
Coherent’s PowerMax PC application software provides a virtual
instrument interface for sensors that enable the operator to take laser
power readings, log data, and compute measurement statistics.
Users can also write their own software using host interface
commands that control all aspects of power meter operation.
For the first time, separate electronics are no longer required
between the sensor and a PC. For those customers who can use a PC
for monitoring laser power, these sensors offer significant cost
savings, space savings, and no reduction in performance.
Product Overview
Product Features
PowerMax-USB provides direct USB 2.0 connection to a PC.
•
Power is provided via USB connection.
• PowerMax-RS provides RS-232 connectivity. Power input is
provided by a +5VDC input (power supply is available as an
optional accessory).
• Instrumentation platform is compatible with thermopile and
optical sensors and can be adapted to most power sensors that
Coherent manufactures.
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PowerMax-USB/RS User Manual
• Displays beam position with position-sensing quadrant ther-
• High resolution 24-bit A/D converter supports four digits of
• Sensors include spectral compensation for accurate use at
• Thermopile sensors include a speed-up algorithm that speeds
• LED status indicators inside USB and RS-232 connectors
• Thermopile sensors offer long-pulse joules capability.
mopiles (such as LM-model sensors like the LM-10).
resolution and measurement accuracy equivalent to that found
in Coherent's LabMax meters.
wavelengths that differ from the calibration wavelength. Each
sensor receives a unique spectral compensation curve specific
to the responsivity of its specific element, as well as transmission characterization of any associated optics.
up the natural response of the thermopile detector without
overshoot.
provide health-and-status information.
Software Features
Plug-and-play application software is supplied standard and
includes the following features:
• Trending
• Statistics (mean, minimum, maximum, and standard devia-
tion) and log batch to file.
• Tuning
• Display beam position on position-sensing thermopiles and
log results to file
• Histogram
• Simultaneously operate multiple sensors
4
Description
• Perform synchronized ratiometery (A/B analysis). Trend and
log results to file.
• For LaserPAD or SSIM customers, the host command set
includes drop-in compatibility.
For system integrators and for implementations involving
customer-written software, the sensors incorporate a comprehensive
command set that is easy to access:
• Utilized a Window USB driver and supports simple ASCII
host commands for remote interfacing using both
PowerMax-USB and PowerMax-RS sensors.
• Using customer-written software, the remote interfacing host
command set allows sensors to be remotely controlled.
• National Instruments
LabVIEW integration.
™
LabVIEW™ driver is supplied for easy
Technical Description
Thermopile Technology
Thermopile sensors are a great all-purpose technology suitable for
many lasers. They are used for measuring CW laser power, average
power in pulsed lasers, and are often used to integrate the energy of
long pulses. Thermopile sensors absorb incident laser radiation and
convert it into heat. This heat ultimately flows to a heat sink that is
held at ambient temperature by either convection-cooling or
water-cooling. The temperature difference between the absorber and
the heat sink is converted into an electrical signal by a thermocouple
junction.
Thermopiles operate across a wide range of input powers, and unlike
a photodiode-based sensor they will not saturate. The spectral range
is dependent upon the coating applied to absorb the laser power. The
coating used on many thermopiles is broadband in nature and is relatively flat from the ultraviolet through the infrared.
These sensors have natural response times on the order of several
seconds for a low power sensor and up to one minute for a kilowatt
sensor. The exponential nature of the natural thermopile output
allows one to electronically accelerate the voltage to its final value
ahead of the actual sensor signal using a software algorithm. We
typically call this capability a “speed-up” algorithm. When
combined with the PowerMax-USB and PowerMax-RS circuitry, a
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PowerMax-USB/RS User Manual
speed-up algorithm can be applied to provide a much faster
response—on the order of seconds or less for most thermopile
sensors. This feature can be turned on and off in the software.
Coherent has two main types of thermopile sensors:
• The LM Model line utilizes a unique thermopile disk in which
• The PM Model line incorporates traditional thermopile disks
PowerMax-USB and PowerMax-RS sensors can use both types of
sensors.
Long-Pulse Energy Measurement With a Thermopile
the thermocouples are split into four quadrants, allowing the
sensors to provide beam position information in addition to
power measurement.
that provide power measurement without beam position information.
Thermopile sensors are most commonly used for average power
measurements on pulsed and CW lasers. A unique capability of thermopile sensors is the ability to integrate the power of a single “long”
laser pulse (long pulse refers to pulses roughly 1 millisecond up to
several seconds in pulse length). The instrumentation analyzes the
output of the thermopile and applies the integration through the use
of an algorithm that results in a Joules reading. This allows the thermopile to measure the energy of single pulses between 1 millisecond
and 10 seconds in length, and with energies from millijoules to
6
Description
hundreds of Joules. The measurement accuracy of this mode is typically better than ± 3% when performed with PowerMax-USB and
PowerMax-RS sensors.
This capability is very useful for what are commonly called
long-pulse medical or industrial type lasers. Common applications
for this type of measurement are in the medical field—especially
skin resurfacing and hair removal—and in material processing
applications, such as laser welding. These laser systems often utilize
high-energy lasers that have large beam sizes and relatively long
pulses.
This type of measurement requires careful selection of the appropriate power sensor, based upon the laser pulse being measured. A
good “rule of thumb” for using a thermopile for this type of
measurement is to compare the maximum pulse energy you need to
measure (in Joules) with the maximum power rating of a sensor (in
Watt s).
Often times a sensor like the PM150-50C is ideal for these measurements. It features a large 50 mm aperture size, can handle pulse energies up to 150J, and can be used air-cooled for single pulse energy
measurements. A PM150-50C normally needs to be water-cooled
for continuous power measurements. The PS19Q sensors, on the
other hand, allow long-pulse measurements down into the mJ level.
Semiconductor Technology
Thermopile joules mode specifications for several PowerMax-USB
and PowerMax-RS sensor can be found in Table 14 on page 77. For
an up-to-date list of all compatible sensors and their specifications,
visit out website: www.Coherent.com/LMC.
Semiconductor photodiode-based sensors convert incident photons
into current that can be measured by our instrumentation. We typically refer to these devices as optical sensors or quantum sensors.
The photodiodes used in these types of sensors offer high sensitivity
and low noise, enabling them to detect very low light levels. The
UV/VIS optical sensor in the PowerMax-USB line is designed to
measure power of CW sources, as well as the average power of
pulsed sources, as long as the repetition rate is above 100 pps. Photodiodes also have a fast response time, making this senor convenient
for tuning and peaking lasers.
These types of sensors have several orders of magnitude higher
sensitivity than thermopile sensors and are quite stable. They do,
however, suffer from photocurrent saturation. The UV/VIS sensor
incorporated into the PowerMax-USB product line includes an
attenuating filter that allows the sensor to be used into the hundreds
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PowerMax-USB/RS User Manual
of milliwatt level without saturation. This ND filter, and the light
shield threaded onto the front of the sensor, also help to block stray
light, thereby resulting in a lower noise floor.
We incorporate spectral compensation in the PowerMax-USB and
PowerMax-RS UV/VIS sensor to provide accurate measurements
across the 325 to 1065 nm spectrum. Because the spectral response
of the ND filter and photodiode varies significantly across this
wavelength range, it is important to check the maximum measurable
power at the wavelength of use to make sure the sensor is not being
saturated. Figure 2, below, indicates the maximum and minimum
measurable power levels by wavelength.
The following curve plots the maximum measurable power—which
is the saturation level of the photodiode—as well as the minimum
recommended power level, by wavelength.
Figure 2. Saturation Power and Minimum Power for PowerMax-USB UV/VIS Quantum Sensor
UV/VIS Temperature Linearity: Like all silicon photodiodes, the
UV/VIS Quantum sensor has temperature sensitivity in the infrared
region. At 1064 nm, for example, it has a 0.5%/ºC thermal coefficient. Due to the electronics inside the sensor, measurement error of
up to 2% is present at 1064 nm after a 10-minute warm-up time.
Additional error can be present if the ambient measurement environment differs from the calibration wavelength listed on the calibration
certificate.
8
Description
In practice, wavelengths shorter than 1000 nm have insignificant
effects due to temperature.
The following figure references the thermal coefficient at the wavelength of use.
Figure 3. Photo Sensitivity Temperature Characteristics
Applying Wavelength Compensation Accuracy
Overall measurement accuracy is a combination of:
• Calibration uncertainty. Note: Specifications for several
sensors are available in Table 14 on page 77. For an up-to-date
list of all compatible sensors and their specifications, visit out
website: www.Coherent.com/LMC.
• Wavelength compensation accuracy (refer to Table 1 on
page 10).
The combined accuracy is based upon practices outlined in the
National Institute of Standards Guidelines for Evaluating and
Expressing Uncertainty (NIST Technical Note 1297, 1994 Edition).
The combined accuracy of the measurement is calculated by using
the law of propagation of uncertainty using the
“root-sum-of-square” (square root of the sum of squares), sometimes described as “summing in quadrature” where:
Measurement Accuracy =
U
2
2
W
+
where:
U = Percent Calibration Uncertainty
W = Wavelength Accuracy
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PowerMax-USB/RS User Manual
Example:
PowerMax-USB LM-10 used at 1064 nm
U = 2%
W = 1.5%
Measurement Accuracy = %
Coherent uses three primary coatings to capture the incident radiation on our thermal sensors. The specifications for each sensor list
which coating is used. Typical wavelength ranges and response
curves for these coatings are shown in Figure 4, below. Each sensor
contains a spectral curve generated from reflectance measurements
taken with spectrometers. The reflectance data are converted into a
wavelength compensation look-up table that is loaded into the
sensor. This data is accessed by selecting a wavelength of operation
in the software.
2
2
2
1.5
+ 42.3+ 2.5==
Figure 4.
All PM- and LM-model thermopiles ± 1.5% 10600
PS model ± 1.5% 514
UV/VIS optical model ± 4% (325 to 900 nm)
a. Refers to wavelengths other than the calibration wavelength.
RV Spectral Correction for Thermal Sensors (Normalized to Calibration Wavelength)
Table 1 lists the spectral compensation accuracy for each type of
sensor.
Table 1. Wavelength Compensation Accuracy
SENSOR
Wavelength Compensation Accuracy
± 5% (900 to 1065 nm)
10
a
CALIBRATION WAVELENGTH (nm)
514
OPERATION
In this section:
• LED status indicators (this page)
• Powering PowerMax-RS sensors (page 12)
• Extending cable length (page 12)
• How to take a power measurement (page 13)
• Zeroing (page 18)
• Setting the wavelength (page 18)
• Using the software (page 19)
Operation
LED Status Indicators
Blue LED lights are contained within the PowerMax-USB and
PowerMax-RS connectors to provide health-and-status information.
PowerMax-USB LED Lights
Blue LED
Table 2. PowerMax-USB LED Light Conditions
LED LIGHT CONDITION STATUS
No light visible If the PowerMax-USB sensor is connected to the PC but there are no visible lights, the sensor is not
powering up properly. Test the sensor on another USB port and if that does not solve the problem, contact
Coherent for service (refer to Table 13 on page 76 for contact information).
Lights flashing slowly (0.5 Hz) Sensor is functioning; however, the driver has not been properly loaded. First, make sure power is being
properly applied to the USB port. If that does not solve the problem, remove the sensor from the USB port
and reinstall the software from the CD that shipped with the product (or download the latest software from
our website: www.Coherent.com
).
Blue LED
Lights slowing ramping up and
down in intensity
Lights flashing fast (10 Hz) The sensor is taking power measurements and sending data over the host port.
Sensor is functioning and the driver has been properly loaded.
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PowerMax-USB/RS User Manual
PowerMax-RS LED Lights
Table 3. PowerMax-RS LED Light Conditions
LED LIGHT CONDITION STATUS
No light visible If + 5VDC has been applied to the PowerMax-USB sensor but there are no visible lights in the connector,
the sensor is not powering up properly. Contact Coherent for service (refer to Table 13 on page 76 for
contact information).
Blue LEDs
Lights slowing ramping up and
down in intensity
Lights flashing fast (10 Hz) The sensor is taking power measurements and sending data over the host port.
Powering
PowerMax-RS
Power has been applied to the sensor and it is functioning.
The PowerMax-RS sensor is powered via a +5 VDC power supply
input.
Sensors
Sensor power cable
Power supply
Extending Cable Length
USB sensors: The PowerMax-USB cable is 2.5 meters in length.
USB hubs can be employed to extend the length of the cable. The
USB standard allows for up to five hubs—connected in series with
5-meter cables connecting the hubs—thus providing a maximum
range of 27.5 meters.
There are also active 5-meter USB extension cables on the market
that perform as if they were a USB hub, but for just a single USB
sensor. (Feel free to contact Coherent for advice related to particular
hubs we have tested in-house.)
12
Operation
RS sensors: The RS cable is 300 mm in length. It is intended to be
used with a standard off-the-shelf RS-232 extension cable to extend
the length.
How to Take a Power Measurement
This section presents two “mini-tutorials” that explain how to
connect a PowerMax-USB or PowerMax-RS sensor to your PC and
begin taking measurements using the PowerMax PC software.
For instructions on communicating with the sensor directly via
host commands, refer to “Host Interface” on page 51.
Tutorials include:
• Measuring power with a PowerMax-USB thermopile sensor.
• Measuring power with a PowerMax-RS thermopile sensor.
Follow all laser safety procedures. The laser must be switched
OFF or shuttered before running the tutorials presented in this
section.
Measuring Power With a PowerMax-USB Thermopile Sensor
This tutorial describes how to take a power measurement using a
PowerMax-USB thermopile sensor.
Verify the laser is switched OFF or shuttered before starting this
tutorial.
1. Install the PowerMax PC software (for detailed installation
instructions, refer to the PowerMax-USB/RS Software Instal-
lation and Quick Start Guide—part number 1169931—that
shipped with your system).
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PowerMax-USB/RS User Manual
2. Plug in the PowerMax-USB
3. When the Found New
sensor.
Hardware Wizard screen
appears, click “Install the
software automatically
(Recommended)” and
then click the Next button
to continue.
This screen display while the
installation program searches for
the PowerMax-USB sensor.
4. Click the Continue Anyway
button to proceed with the
installation.
5. Click Finish to complete the
installation.
14
Operation
6. Confirm the blue LEDs on the USB
Blue LED
connector are lit and slowly ramping up
and down in intensity (which signifies
the sensor is working and the driver is
Blue LED
properly loaded).
7. Run the PowerMax PC software.
8. Select the sensor serial
number from the Select Sensor
dropdown menu. In the
example at right, the selected
sensor serial number is
0347E09.
9. Press the Zero Sensor button to zero out any offset in the
sensor.
10. Press the Start Data Collec-
tion button and then turn ON
the laser to begin taking
power measurements.
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PowerMax-USB/RS User Manual
Measuring Power With a PowerMax-RS Thermopile Sensor
This tutorial explains how to take a power measurement using a
PowerMax-RS thermopile sensor.
Verify the laser is switched OFF or shuttered before starting this
tutorial.
1. Install the PowerMax PC software (for detailed installation
instructions, refer to the “Software Installation” section of the
PowerMax-USB/RS Software Installation and Quick Start
Guide—part number 1169931—that shipped with your
system).
2. Plug the PowerMax-RS
sensor into an available
RS-232 COM port on the
computer.
3. Plug the +5V DC power supply
cable into the sensor power cable
and the power supply into a wall
electrical outlet. (The power
supply is available from Coherent
as an optional accessory—part
number 1105557.)
Power supply
4. Confirm the blue LEDs on the RS
connector are lit and slowly ramping up
and down in intensity (which signifies the
sensor is working and the driver is properly loaded).
5. Run the PowerMax PC software.
Sensor power cable
Blue LEDs
16
Operation
6. Click Show RS-232 Ports
from the Settings dropdown
menu. The software will scan
COM ports for PowerMax-RS
sensors.
7. Select the COM port to which
the PowerMax-RS sensor is
attached. In the example at
right, the selected COM port is
COM1.
8. Insert the sensor into the beam path, making sure the laser is
turned OFF or shuttered until the sensor is zeroed.
9. Press the Zero Sensor button to zero out any offset in the
sensor.
10. Press the Start Data
Collection button and then
turn ON the laser to begin
taking power measurements.
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PowerMax-USB/RS User Manual
Zeroing
Pressing the Zero button implements the Zero function and sets the
current sensor input as the baseline for future measurements. It is
recommended that you zero the sensor after first turning it on and
before beginning any new set of power measurements.
When a zero procedure is in process, no other button events are
queued or activated until the procedure ends. The zero procedure
immediately terminates if the sensor is disconnected or if an error is
encountered.
Normally you should press the Zero button while the laser is turned
off, or while the laser beam is blocked. If a finite power level is
present at the sensor, the instrumentation will attempt to null it out.
The sensor can only zero a finite level of offset equivalent to approximately 10% of full scale range.
If zeroing is unsuccessful—which means that the power input is
too large to null—re-zero in a more stable environment or select
a different range.
Setting the Wavelength
The wavelength should always be set for accurate power measurements. This can be done either in the PowerMax PC application software or over the host port via a host command.
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Using the Software
Operation
Front Panel
The Front panel (shown in Figure 5) is the first screen that appears
once the software is launched. From here you can enter parameters,
select modes, change ranges, start/stop data acquisition, and view
the output in a chart format.
Figure 5. Front Panel
Individual functions accessed through the Front panel are discussed,
starting next.
Keyboard Shortcuts The following table shows available shortcuts for several standard
functions:
Table 4. Keyboard Shortcuts
FUNCTION SHORTCUT
Exit program <Ctrl>+<Q>
Open new Front panel <Ctrl>+<N>
Print window <Ctrl>+<P>
Show context help <Ctrl>+<H>
View full application <Ctrl>+<F>
View saved data file <Ctrl>+<V>
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