Mobile Device Power Monitor Manual - Monsoon Solutions

Mobile Device Power Monitor Manual
Distributed By:
Monsoon Solutions, Inc.
2405 140 th Avenue NE
Suite A115
Bellevue, Washington 98005
(425) 378-8081
www.msoon.com

1
Table of Contents
Mobile Device Power Monitor Manual ...................................................................... 0
Revision History .............................................................................................. 2
Introduction ................................................................................................... 3
Hardware and Software Requirements for the Development Workstation ................ 5
Installing the Software and Connecting the Hardware .......................................... 6
Obtaining the Software for the Power Tool ..................................................... 6
Connecting the Mobile Device Power Monitor Hardware ................................... 7
Connecting the Mobile Device Power Monitor to a Device ...................................... 9
Using the Power Tool Software ........................................................................ 10
Checking the Software Revision of the Power Monitor ........................................ 11
Powering-up and Powering-down a Mobile Device ......................................... 12
Over-Current Error from the Main Power Supply ........................................... 13
Protecting the Main Power Supply from an Over-Current Error .................. 14
The Legend Dialog Box .................................................................................. 15
Sampling Data ......................................................................................... 16
Markers .................................................................................................. 16
Statistics ................................................................................................. 17
Zoom ................................................................................................. 18
USB Pass-Through .................................................................................... 19
USB Pass-Through: Modes.................................................................... 19
Measuring USB Power .......................................................................... 21
Using USB Markers .............................................................................. 21
Auxiliary Port (Aux) .................................................................................. 22
Data Importing Features of the Power Monitor ............................................. 23
Data Exporting Features of the Power Monitor.............................................. 24
Functional Description of the Mobile Device Power Monitor ................................. 25
APPENDIX: ........................................................................................................ 26
Electrical Specifications of the Mobile Device Power Monitor ................................ 26
Main Channel ........................................................................................... 26
USB Channel ........................................................................................... 27
Auxiliary Channel ..................................................................................... 28
Power Monitor Data and Control Protocol .......................................................... 29
Command Line Operation of the Power Monitor ................................................. 29
Power Monitor Exit Codes ............................................................................... 33
PT4 file format .............................................................................................. 33

2
Document Revision History
Date Released Revision Number Notes
May 2007 1.0 Initial release
November 1, 2007 1.1 Updated features and added PT4 formats
January 16, 2008 1.2 Updated path for Power Monitor Install
directory
July 15, 2008 1.3 Updated and added features
November 9, 2009 1.4 Corrected web site links

3
Introduction
The Power Tool software and the Mobile Device Power Monitor hardware provide a robust
power measurement solution for Windows Mobile powered devices. The Power Tool software
and the Mobile Device Power Monitor hardware can analyze the power on any device that
uses a single lithium (Li) battery. Electrical engineers and software developers can utilize
the Power Tool software and the Mobile Device Power Monitor hardware to optimize the
design and analyze the performance of their Windows Mobile powered devices.
Figure 1: Graphical user interface (GUI) for the Power Tool

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Figure 2: Mobile Device Power Monitor hardware

5
Hardware and Software Requirements for the
Development Workstation
A dedicated workstation is required to be used with the Mobile Device Power Monitor to
achieve the optimal performance and results.
• Microsoft Windows XP SP2, Windows Vista and Windows 7 is supported
• 1 GHz 32-bit (x86) or 64-bit (x64) processor
• 1 GB of system memory
• 40 GB hard drive with at least 15 GB of available space
• Full Speed USB 1.1/USB 2.0 – integrated chipset or PCI/PCI Express add in card. USB
Hubs should not be used with the Mobile Device Power Monitor

Installing the Power Monitor Software and Connecting the
Hardware
Obtaining the Software for the Power Tool
6
To obtain the latest software version for the Mobile Device Power Monitor
hardware
1. Go to http://www.msoon.com/register/download/ , then click on the PowerMonitor
Software link and download PowerTool_4.x.x.zip. Uninstall any previous version of
the Power Monitor Software.
2. Create a new folder on the development workstation called PowerTool under the root
directory (C:\).
3. Copy PowerTool.zip to the development workstation.
4. Extract the contents of PowerTool.zip to the C:\PowerTool folder.
5. Run PMSetup.msi
6. Follow the on screen prompts to Install the Power Tool Software

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Figure 3: Installation.
Connecting the Mobile Device Power Monitor Hardware
To connect the Mobile Device Power Monitor hardware
1. Be sure that the power switch on the front of the Mobile Device Power Monitor hardware
is not engaged. The hardware should not be powered-up.
The power switch should be in the outward position, not the inward position.
2. Connect the 6 volts (V) of direct current (DC) and 5 ampere (A) power supply to the
Mobile Device Power Monitor hardware.
3. Connect the 6 VDC and 5 A power supply to an alternating current (AC) power supply.
4. On a development workstation that is compliant with Full-Speed USB 2.0, connect a USB
cable to the USB connector on the back of the Mobile Device Power Monitor hardware,
and connect the other end of the USB cable to the development workstation.
Figure 4: Back view: Power connector and USB connector
5. Turn on the Mobile Device Power Monitor hardware by engaging the power button on the
front. The internal fan will briefly power-up and then power-down.
Initially, the power light-emitting diode (LED) is orange, and then it turns green. The
green LED is connected directly to the internal power of the Mobile Device Power
Monitor.

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Figure 5: Front view: Engaged power button and powered-up green LED.
Installing the Power Monitor driver on a workstation
1. After running the setup program power up the Mobile Device Power Monitor and if the
Power Monitor is being installed for the first time on the workstation, the “Found New
Hardware” Wizard will launch.
2. On the Found New Hardware Wizard, do not choose to have the device drivers installed
automatically, choose “No, not this time” and then select “Next”.
3. On the next prompt of the Found New Hardware Wizard, choose “Install from a list or
specific location (Advanced)”, and then select Next.
4. On the next prompt of the Found New Hardware Wizard, choose “Don’t search. I will
choose the driver to install” and then select “Next”.
5. On the Hardware Type page, choose “Show All Devices”, and then select “Next”
6. On the next prompt, choose “Have Disk”.
7. From the Install from Disk window, choose the “Browse” button, and navigate to the
folder where the extracted contents of PowerTool.zip were saved.
8. Select the corresponding Operating System folder in C:\Program Files\Monsoon
Solutions, INC\, select the Mchpcdc.inf file, and select “Open”.
9. Choose “OK”
10. From the Found New Hardware Wizard, choose “Next”
11. If a warning is received about an unsigned driver, select “Continue Anyway”
12. In the Found New Hardware Wizard, select “Finish”.
After installing the driver choose Finish. The Power Tool software is installed.

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Connecting the Mobile Device Power Monitor to a Device
It can take 30 minutes or longer to configure a good test connection. A device that can
measure voltage and resistance, such as a voltmeter/ohmmeter will be needed.
Note Wear safety goggles at all times while working with exposed battery terminals
and wiring.
**************************************************************
Connecting the Mobile Device Power Monitor to a device to collect current
measurements can be complicated and dangerous. Be sure that the area where
power measurements are being conducted is protected from fire danger, do not
have flammable items nearby. These measurements are at your own risk, and
these procedures are not guaranteed to prevent damage or injury
**************************************************************
Note There is no way to guarantee a proper connection. When attaching the power
measurement hardware to a device with a lithium battery, there is always a risk of
damaging the device, or causing the device to heat-up, generate smoke, or catch fire.
While this is unlikely, be extremely careful, and if anything gets hot, immediately
remove the battery and the power source.
The following guide details and outlines how to prepare the device to connect to the Mobile
Device Power Monitor.
http://www.msoon.com/LabEquipment/PowerMonitor/downloads/quickstartguide.pdf

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Using the Power Tool Software
After connecting the device, power up the Mobile Device Power Monitor and run the Power
Tool software (PowerTool.exe). The software should connect to the Mobile Device Power
Monitor, and display the user interface (UI).
Figure 6: Power Tool software UI after connecting to a device

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Checking the Software Revision of the Power Monitor
The revisions of the hardware (HW ver), firmware (FW ver), and software (SW ver) should
be compatible for consistent and repeatable results and performance.
If the Mobile Device Power Monitor software is updated, the firmware will need to be
confirmed for compatibility. The Mobile Device Power Monitor will prompt the user to
indicate that a new firmware is required to run this revision of software. If this occurs, then
the firmware (FW ver) will need to be updated on the Mobile Device Power Monitor. Please
follow the instructions on updating the Mobile Device Power Monitor at the following
location: http://www.msoon.com/register/download
The following table describes the various revision numbers that are displayed in the UI.
Field Description
HW rev Power Monitor hardware revision
FW ver Power Monitor firmware version
Prot ver Version of protocol specification
SW ver Power Tool UI version
HW rev SW ver Firmware Version
B, C, D 3.0.4 12
B, C, D 4.0.2, 4.0.1 17, 18
B, C, D 4.0.3 19
To make sure the correct software is installed, check the revision fields in the UI. Figure 7
below shows the area of the UI that displays the software revision.
Figure 7: Revision fields shown in the Power Tool UI.

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Powering-up and Powering-down a Mobile Device
To power-up the device, first set the Vout voltage. The voltage can be set from 2.1 V to 4.5
V in .01 V increments. The maximum voltage of a lithium battery is usually 4.2 V, so set the
Vout voltage somewhere between 3.3 V and 4.2 V.
To enable the power, click the Vout Enable button, to disable the power, click the Vout
Disable button.
Figure 9: below shows the location of the Vout Enable, which toggles when it is clicked to
the Vout Disable button.
Figure 8: Vout Enable and Vout Disable button.
The voltage at the red and black terminals is never exactly at the programmed voltage. This
is because there is an internal 0.056 Ω sense resistor in series with the regulator. For
example, if the device is drawing 1 A when Vout equals 3 V, expect to see (3 - 1*.056) =
2.944 V. Figure 10: below shows this sense resistor in series with the regulator, in relation
to the red and black terminals.
Figure 9: Sense resistor in series with the regulator, in relation to the red and
black terminals.
There is resistance in the wiring that can lower the voltage at the device. The resistance of
the wiring plus the sense resistor is similar to the resistance of the lithium battery in the
device; batteries are usually about 0.12 Ω.

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The resistance of 20 gauge wire is 0.012 Ω/ft, so if the cables are 20 gauge, and 1 foot in
length, that adds another 0.024 Ω, in addition to the contact resistance.
Figure 10: Vout LED indicator
If the power-up is successful, the green Vout LED indicator in Figure 10 above will powerup.
This LED is connected directly to Vout, so the light will dim slightly if the voltage is
lowered. If this LED does not power-up, then Vout did not power-up properly, so there are
other problems.
Over-Current Error from the Main Power Supply
Sometimes an over-current error occurs when powering-up. When an over-current error
occurs, the amber LED powers-up, and the green LED for Vout powers-down.
An over-current error can happen when the:
• Device is attached backwards.
• Device is attached incorrectly.
• Device has a lot of capacitance, a very high in-rush current.
• Device has an unusually high run current.

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Figure 11: Amber LED indicator for over-current.
Note Be sure to check for a backwards connection before overriding the over-current
limits.
Protecting the Main Power Supply from an Over-Current Error
The main power regulator can source 3.0 A of continuous current and 4.5 A of peak current.
In order to protect incorrectly connected devices from damage, a carefully controlled power
up sequence is used. The default sequence is as follows:
1. Power up with no current limit for 20 milliseconds
2. Run for 1 second with the current limit set to 500 mA
3. Run continuously with the current limit set to 4.6 A
The parameters in the dialog box below are used for device under test power on.
1. Power up time – This specifies the power up time when no current limit is applied to the
Mobile Device Power Monitor.
2. Power up Current Limit – If the Power Up Time is set to default, this parameter will allow
the selected current to be supplied to the device for 1 second.
3. Run time Current Limit- This parameter specifies what the maximum current that can be
sourced by the Mobile Device Power Monitor while its sampling or in “Run” mode.
If a device does not power up with this default profile, the profile may be adjusted. Click on
Parameters in the UI and the dialog box shown below in Figure 12:

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The Legend Dialog Box
Figure 12: Dialog box for over-current.
The Legend dialog box controls which channels are displayed, and what kind of data is
shown in the graph.
Figure 13: Dialog box for the display Legend.

Sampling Data
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To begin sampling data, click the Run button. To stop sampling, press the Stop button.
Figure 14 below shows the Run button, which toggles to the Stop button once it is clicked.
Figure 14: Run and Stop toggle button.
The calibration indicator indicates that the unit has a valid and unexpired calibration date
and functioning auto-calibration hardware. Figure 15 below shows the calibration indicator.
Figure 15: Calibration indicator.
The serial number displayed in the UI, and shown in Figure 16 below, is the serial number of
the Mobile Device Power Monitor hardware. It is programmed to a unique number in the
factory. If the firmware is upgraded improperly in the field, the factory serial number may
be incorrect. If this happens, it is advisable to contact Monsoon Solutions, Inc., because the
factory calibration settings may have also been lost.
Markers
Figure 16: Serial number.
Markers enable users to measure the delta (Time and selected data channel) between two
points on the power monitor output data plot.
1. Drag the red and blue arrows (indicator) to the desired position on the power monitor
output data plot
2.The Delta will be displayed under the Selection Statistics section.

Statistics
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Figure 17: Capture statistics.
Battery life, current, and power statistics for the Main channel are visible in the STATS area
of the UI. The user first sets the battery capacity and then runs the Power Monitor. If there
is no region selected, the statistics will be associated with the entire run as in Figure 18
below.
Figure 18: Capture statistics.
If a smaller area is selected with the mouse on the graph, then the statistics are computed
only for the selected area, as shown in Figure 19 below.

Zoom
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Figure 19: Selection Statistics.
Selecting a certain area with the mouse on the graph and by either double clicking or
selecting the scroll mechanism on a mouse (if one is available) will zoom in on the selected
area. The statistics are computed only for the selected area, as shown in Figure 20 below.
Figure 20: Zoom capabilities.

USB Pass-Through
USB Pass-Through: Modes
19
In addition to the Main channel, three other channels are sampled at the same time. One of
these is used for monitoring USB power. To use the USB Pass-Through mode, connect the
USB device to the Mobile Device Power Monitor, and connect a USB cable from the Mobile
Device Power Monitor to the development workstation as shown in Figure 20 below.
Figure 21: USB pass-through connection

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To download code or data when testing a device, USB can be used to connect the device to
the Mobile Device Power Monitor. However, when connecting to USB, USB charges the
device, which disturbs the current measurements. To remedy this, the Mobile Device Power
Monitor has an Auto USB passthrough mode. Auto USB passthrough mode is useful
for testing, because in Auto USB passthrough mode, the USB pass-through is
disconnected whenever sampling starts. After sampling has completed, USB is reconnected
automatically so that test data can be loaded to the device. The Auto USB passthrough
mode setting is shown in below in Figure 22.
Figure 22: USB pass-through control
In addition to Auto USB passthrough mode, there are two other USB modes:
• On: Setting the USB passthrough mode to On enables the USB connection and
records the current flowing through the USB connector on the front of the Mobile Device
Power Monitor.
• Off: Setting the USB passthrough mode to Off disables the USB connection.

Measuring USB Power
21
The USB connection can be used to measure the power and current on any functioning
attached USB device. For example, the current and power of a mouse can be monitored as
it is used by selecting USB in the Legend dialog box, and setting the USB passthrough
mode to On in the Parameters dialog box.
Figure 23: Testing a USB peripheral with the Mobile Device Power Monitor
Using USB Markers
If synchronizing an external event is required, the Power Tool software can support that
feature over USB with Markers.
To use the Markers functionality:
1. Set the USB passthrough mode to Off.
2. Select the Markers checkbox in the Power Monitor UI.
3. Connect transistor-transistor logic (TTL) signals from the device to the USB A-connector
on the front of the Mobile Device Power Monitor. An easy way to do this is to use an old
USB cable and cut it.
Signals that are driven on the data lines will be shown as highs (1s) or lows (0s) on the
display. There are wide blue and red lines for the Markers.

Auxiliary Port (Aux)
22
The Aux port is connected to the bayonet Neill-Concelman (BNC) connector on the front of
the Mobile Device Power Monitor. It allows for simultaneous measurement of the current
going through an external power supply.
For example, suppose the LT1129 shown below in Figure 24 sits on a mobile device PCB and
the current supplied to the 3.3 V supply needs to be measured.
Figure 24: Schematic of the Aux port
In this situation, to measure the current supplied to the 3.3 V power supply, connect a 50 Ω
coaxial cable to a 0.1 Ω sense resistor and connect that coaxial cable to the Mobile Device
Power Monitor. When connecting a coaxial cable:
• Connect the outside of the BNC connector to the high side of the sense resistor.
• Connect the inside of the BNC connector to the low side of the sense resistor.
In Figure 25 below, the mobile device is powered by the Mobile Device Power Monitor and
its processor core power is being monitored on the Aux port with a 0.1 Ω resistor. In the
Mobile Device Power Monitor, the data for the main supply and the core supply can be
displayed and analyzed simultaneously.

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Figure 25: Example connection to the Aux port
Data Importing Features of the Power Monitor
The data importing features of the Power Monitor allows the user to import data from the
following data formats:
The Power Tool software can import the file formats shown in the following table.
File format Description
.PT3 Binary data in exactly the same format
that the Power Monitor creates, this is
compatible with the current version of
the protocol specification.
All of these formats, when saved, are saved at the maximum time resolution, regardless of
the Capture Settings.
The Mobile Power Monitor will convert the imported file to a .PT4 format before displaying
the output to the display box.

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Figure 26: Importing PT3 file extension
Data Exporting Features of the Power Monitor
The data exporting features of the Power Monitor allows the user to save data for the
following:
• The entire power measurement run
• If any data is selected with the mouse, the selected data is exported
• If no data is selected with the mouse, then the data that is displayed
The Power Tool software can export to the file formats shown in the following table.
File format Description
.PT4 Binary data in exactly the same format
that the Power Monitor creates, this is
compatible with the current version of
the protocol specification. Please see the
APPENDIX for a more detailed breakdown
of the PT4 format
.CSV Comma-separate values. A common
format that can be used to import into
spreadsheet software. The Power Monitor
saves only what is recorded in the
current trace.
.DCF A common format for exporting test
data.
All of these formats, when saved, are saved at the maximum time resolution, regardless of
the Capture Settings.

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Functional Description of the Mobile Device Power Monitor
To measure the current accurately, a dual range, self-calibrating, integrating system is
used. Each channel has two current ranges with a 16-bit analog-to-digital converter (ADC),
one with a high-resolution range, and the other with a low-resolution range. Software
continuously calibrates each of these and selects the proper range during measurement.
The dual range scheme works because mobile devices are usually in standby mode and
drawing only a few millamps of current, or they are running above 100 milliamps. The
Mobile Device Power Monitor must be very accurate when the current is low, but may be
less accurate as the current increases. Each sample is integrated over its 200-microsecond
sample period so that even a brief high-current pulse is captures. Depending on system
capacitance and other factors, the fastest transient pulses are around 20 microseconds. The
integrator sums up these fast pulses so that an accurate assessment of the average current
is maintained. The unit is self-calibrating. One cycle out of every 1000 cycles is used to run
either a zero-current calibration or a reference-current calibration. Software uses these
measurements to null out the offset and gain errors in the system. Because this is done
automatically, it compensates for slow temperature changes during the measurement run.
The only part not included in the self-calibration is the sense resistor. These resistors are
calibrated at the factory and the calibration values may be adjusted and saved by engineers
using the Parameters dialog box. The Power Monitor has an overflow buffer that can hold six
packets of 128 bytes each. During transfer, if the development workstation cannot read the
data fast enough then this buffer will begin to fill up, and samples may be lost. The received
data is concatenated so the line appears continuous. To account for the lost samples, the
protocol contains a 16-bit counter that tracks the number of lost samples. The running total
of lost samples is displayed in the UI, as shown in Figure 27 below.
Figure 27: Counter for dropped samples and dropped connections
Because the dropped samples are less than one percent of a run, the error is minimal.
Usually this loss of data is less than 0.1 percent. However, sometimes on long runs or on
loaded systems the dropped sample count can exceed 65,000. When this occurs, the Power
Tool lost communication for more than 10 seconds. A count of dropped connections is
maintained in the UI, as shown above in Figure 26. Both of these counts are reset to zero
when a run is restarted. These counts are useful to determine how stable the connection is.
If the dropped packets are greater than one percent of all samples, or if there are more
than one or two dropped connections per hour, then it is likely that the development
workstation has other applications running that are causing delays. Closing these
applications or installing the Power Tool software on a clean machine should solve these
issues and reduce the dropped samples and packets.

APPENDIX:
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Electrical Specifications of the Mobile Device Power
Monitor
Main Channel
Component Minimum Maximum
Output voltage range 2.1 V 4.5 V
Continuous current 3.0 A
Peak current 4.5 A
Integrator cutoff
frequency
300 kHz
Fine current scale - range 40 mA
Fine current scale -
resolution
Fine current scale -
accuracy
Coarse current scale -
range
Coarse current scale -
resolution
Coarse current scale -
accuracy
Programmable current
limit range
Programmable current
limit accuracy
Positive temperature
coefficient (PTC) hold
limit at 6 V of direct
current input (DCIN)
2.86 uA
+/- 1% or +/- 50 uA
(whichever is greater)
30 mA 4.5A
286 uA
+/- 1% or +/- 1 mA
(whichever is greater)
8 mA 8 A
(0.7) * (current limit) (1.4) * (current limit)
3 A
PTC trip limit at 6 V DCIN Not applicable 6 A
Fan turn on temperature 38 C
Fan turn off temperature 33 C
Thermal limit shutdown 50 C

USB Channel
27
Component Min Max
Input voltage range 2.1 V 5.4 V
Continuous current 1.0 A
Peak current 4.5 A
Integrator cutoff
frequency
300 kHz
Fine current scale - range 40 mA
Fine current scale -
resolution
Fine current scale -
accuracy
Coarse current scale -
range
Coarse current scale -
resolution
Coarse current scale -
accuracy
VBUS PTC current hold
limit
VBUS PTC current trip
limit
2.86 uA
+/- 1% or +/- 50 uA
(whichever is greater)
30 mA 4.5 A
286 uA
+/- 1% or +/- 1 mA
(whichever is greater)
VBUS capacitance to GND 22uF +/- 20%
0.52 A 0.85 A
1.04 A 1.7 A

Auxiliary Channel
28
Component Min Max
Input voltage range 1.0 V 5.0 V
Differential input voltage 0.1 V
Integrator cutoff
frequency
300 kHz
Fine current scale - range 0 mA 12 mA
Fine current scale -
resolution
Fine current scale -
accuracy
Coarse current scale -
range
Coarse current scale –
resolution
Coarse current scale -
accuracy
2.58 uA
+/- 1% or +/- 50 uA
(whichever is greater)
10 mA 500 mA @ Vin = 1V
100 uA
+/- 1% or +/-1mA
(whichever is greater)
Aux + side capacitance 22uF+/- 20%
1 A @ Vin = 1.8 V
Aux + side input current Not applicable 1% of 0.1 Ω resistor
current

29
Power Monitor Data and Control Protocol
All control of the Mobile Device Power Monitor happens on the development workstation.
The development workstation issues commands and the Mobile Device Power Monitor
responds to the commands by completing the operation and sending back a Status packet.
The Status packet contains the entire current state of the machine, except when sampling.
When sampling, the Power Tool sends a Start packet to the Mobile Device Power Monitor,
and then the Power Monitor sends sample packets continuously back to the Power Tool.
When sampling is to be stopped, the Power Tool UI sends a Stop packet. The Mobile Device
Power Monitor stops sampling and responds with a Status packet. Generally, when the
Mobile Device Power Monitor is not sampling, the Power Tool requests periodic status
packets in order to refresh its display.
Command Line Operation of the Power Monitor
This applies to PowerTool version 4.0.1. Version 4.0.1 includes a console application,
PowerToolCmd, for better execution in batch files/scripts.
The command line format is:
PowerToolCmd [fileName] [switch [switch …]]
where fileName is the optional name of a PT4 file to be loaded into the buffer.
Switches begin with “-“ (hyphen) or “/” (forward slash). The switches are as follows, and
are case-insensitive:
Switch Description
/LOADFILE=file Same as fileName above
/NOGUI Console mode
/ISTART Sampling starts immediately
/TRIGGER=string See section on trigger codes
/TESTMINPOWER=value Return success if average power (mW) is >= value
/TESTMAXPOWER=value Return success if average power (mW) is

30
/TEMPDIR=path Override temporary directory
(Default: %My Documents%\PowerTool)
/USBPASSTHROUGH=mode
/USB=mode
USB passthrough mode: AUTO, ON, or OFF
(Default: AUTO)
/NOEXITWAIT Program exits without waiting for “Press any key…”
/EXITCODES Lists program exit codes
/?, /H, /HELP Lists command-line switches
Trigger codes
The following is the syntax of a trigger code:
{A|Bn|Cqrn|D}[{An|Bn}]T[X]{A|Bn|Cn|Dnt|Eqrn}[An]
The capital letters are literals. “n” represents a numeric quantity (in decimal), and “q”, “r”
and “t” are place-holders for code letters, explained below.
At the highest level, the string breaks down into:
T
The following table lists the possible values of :
Code Meaning
A Manual start
Bn Start after “n” markers
Cqrn Start when quantity “q” has relationship “r” with the number “n” (see below)
D Start immediately
The possible values of (when present) are:
Code Meaning
An Delay capture “n” samples after trigger
Bn Capture “n” samples before trigger
If is present, the value “X” indicates that a DCF file should be
automatically exported when sampling stops.

31
The following table lists the possible values of :
Code Meaning
A Manual stop
Bn Stop after “n” markers
Cn Stop after “n” samples
Dnt Stop after “n” time units of type “t” (see “t” below)
Eqrn Stop when quantity “q” has relationship “r” with the number “n” (see below)
The possible values of (when present) are:
Code Meaning
An Capture “n” samples after trigger
The possible values for the quantity code “q” are:
Code Meaning
A Min power
B Avg power
C Max power
D Min current
E Avg current
F Max current
G Min Vout
H Avg Vout
I Max Vout
The possible values of relationship code “r” are as follows:
Code Meaning
A >=
B

32
The possible values of the time-unit code “t” are as follows:
Code Meaning
A Seconds (s)
B Milliseconds (ms)
C Microseconds (us)
For example, a trigger code “CBA300A500TXC20000A500” would be interpreted as follows:
Code Meaning
CBA300 Start capture after average power falls below 300 mW
A500 Delay capture 500 samples after trigger
T Fixed delimiter
X Auto-export DCF file after stop
C20000 Stop capture after 20000 samples
A500 Capture 500 samples after trigger
The Trigger Settings dialog has a feature that shows the resulting trigger code that
corresponds to the dialog settings.
Capture Data Mask
The capture data mask is a 16-bit quantity that specifies the data to be captured. It can be
expressed either in decimal or hexadecimal (using C-style “0x” notation), but it is most
naturally expressed in hex, since it is a combination of discrete bit values.
The mask indicates which of the three data channels are to be captured: Main, USB, or AUX.
Each channel is represented by one bit in the mask. The mask is thus the bitwise-OR of the
channel(s) to be captured.
The bit values for the channels are as follows:
Mask Channel
0x1000 Main
0x2000 USB
0x4000 Aux
The default value is 0x1777 (the low-order twelve bits are no longer significant)

33
Power Monitor Exit Codes
When the Power Tool is closed, it provides an exit code that indicates why the software was
closed. The exit codes include but are not limited to:
• Test complete OK
• Unable to find hardware
• Hardware calibration failed
• Disk space check fail
• Capture file write error
• Capture hardware error
• Capture buffer overrun
PT4 file format
A PT4 file consists of three main sections:
• A fixed-length header (212 bytes), at file offset 0
• A fixed-length Status packet (60 bytes for Protocol 16), at file offset 272
• Multiple occurrences of variable-length sample data, starting at file offset 1024. All
samples are recorded at a frequency of 5 kHz. Each sample is an n-tuple, the
content of which is selectable at run-time.
Header section
The first 212 bytes are the header, as follows:
Name Description C# data type Bytes File
offset
headSize Header size int 4 0
Name “Power Tool” string 20 4
batterySize mAh int 4 24
captureDate System.DateTime binary long 8 28
serialNumber Power Monitor serial
number
string 20 36
calibrationStatus OK (0) or FAILED (1) CalibrationStatu
s enum
voutSetting Typical (0), Low (1), High
(2), or Custom (3)
VoutSetting
enum
4 56
4 60
voutValue Main voltage output float 4 64
hardwareRate Hz int 4 68
softwareRate Hz float 4 72
powerField Data selection for Power SelectField enum 4 76
currentField Data selection for Current SelectField enum 4 80

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Name Description C# data type Bytes File
offset
voltageField Data selection for Voltage SelectField enum 4 84
captureSetting Trigger specification string 30 88
swVersion Power Tool version string 10 118
runMode NoGUI (0) or GUI (1) RunMode enum 4 128
exitCode Application exit code int 4 132
totalCount Count of data samples long 8 136
statusOffset File offset of Status Packet ushort 2 144
statusSize Size (bytes) of Status
Packet
ushort 2 146
sampleOffset File offset of Sample data ushort 2 148
sampleSize Size (bytes) of each
individual sample
ushort 2 150
initialMainVoltage See Table 6. ushort 2 152
initialUsbVoltage See Table 6. ushort 2 154
initialAuxVoltage See Table 6. ushort 2 156
captureDataMask Mask indicating which data
is being captured (see
Table 3)
ushort 2 158
sampleCount Sample count ulong 8 160
missingCount Count of missing samples ulong 8 168
sumMainVoltage Sum of main output voltage
(V). Divide by
(sampleCount –
missingCount) for Average.
float 4 176
sumMainCurrent Sum of main current (mA) float 4 180
sumMainPower Sum of main power (mW) float 4 184
sumUsbVoltage Sum of USB voltage (V) float 4 188
sumUsbCurrent Sum of USB current (mA) float 4 192
sumUsbPower Sum of USB power (mW) float 4 196
sumAuxVoltage Sum of Aux voltage (V) float 4 200
sumAuxCurrent Sum of Aux current (mA) float 4 204
sumAuxPower Sum of Aux power (mW) float 4 208
Total length: 212
Table 1: Header layout
All strings are length-prefixed (one-byte), and are blank-padded to their fixed length,
suitable for reading with BinaryReader.ReadString(). The lengths listed include the length
byte.

35
The enumerations are as follows:
Enumeration Definition Description
CalibrationStatus OK=0
Failed=1
VoutSetting Typical=0 (3.7 V)
Low=1 (3.35 V)
High=2 (4.2 V)
Custom=3
SelectField None=0x00
Avg=0x01
Min=0x02
Max=0x04
Main=0x08
Usb=0x10
Aux=0x20
Marker=0x40
RunMode NoGUI=0
GUI=1
Table 2: Header enumerations
Status of calibration
Type out Vout setting
Masks describing which
channel
(Main,Aux1,Aux2,Marker)
and statistic
(Avg,Min,Max) are being
recorded
Whether or not PowerTool
was running in GUI mode
The captureDataMask can be interpreted with the following bit masks:
Channel Mask
Main Current 0x1000
Usb Current 0x2000
Aux Current 0x4000
Marker 0x8000
Voltage 0x0700
Table 3: Channel selection masks
For example, if the bitwise-Boolean expression (captureDataMask & x02000) is non-zero,
then current data for the Aux1 channel is being recorded in the file. If (captureDataMask
& 0x0700) is non-zero or (captureDataMask & 0x8000) is non-zero, then voltages and
markers are being recorded in the file. The section on the sample data will explain this
further.
The file is padded with zeros until offset 272 (144+128), where a Status packet from the
Power Monitor hardware is recorded, as follows:
Name Description C# data type Bytes File
offset
packetLength Length-1 of packet (59 byte 1 272 0
Packet
offset

36
for Protocol 16, but may
expand in later
protocols)
packetType 0x10 for Status packet byte 1 273 1
firmwareVersion Firmware version byte 1 274 2
protocolVersion Protocol version byte 1 275 3
mainFineCurrent Main current, fine scale short (signed) 2 276 4
usbFineCurrent Usb current, fine scale short (signed) 2 278 6
auxFineCurrent Aux current, fine scale short (signed) 2 280 8
voltage1 Voltage of selected
channel. See Table 6.
mainCoarseCurrent Main current, coarse
scale
usbCoarseCurrent Usb current, coarse
scale
auxCoarseCurrent Aux current, coarse
scale
voltage2 Voltage of selected
channel. See Table 6.
outputVoltageSetting Volts = 2.0 +
outputVoltageSetting *
0.01
ushort 2 282 10
short (signed) 2 284 12
short (signed) 2 286 14
short (signed) 2 288 16
ushort 2 290 18
byte 1 292 20
temperature Degrees Celsius byte 1 293 21
status Bit flags (low to high):
unitNotAtVoltage
cannotPowerOutput
checksumError
followsLastSamplePacke
t
responseToStopPacket
badPacketReceived
byte 1 294 22
reserved Unused byte 1 295 23
leds Bit flags (low to high):
disableButtonPressed
errorLedOn
fanMotorOn
voltageIsAux
mainFineResistor Resistor offset
(ohms = 0.05 + offset *
0.0001)
byte 1 296 24
sbyte (signed) 1 297 25
serialNumber Serial number ushort 2 298 26
sampleRate kHz byte 1 300 28
dacCalLow DAC input for 2.5 V
output
ushort 2 301 29

37
dacCalHigh DAC input for 4.096 V
output
powerUpCurrentLimit Max current during
power-up
(amps = 8 * ((1limit)/1023)
runTimeCurrentLimit Max current during
sample run (amps = 8 *
((1-limit)/1023)
ushort 2 303 31
ushort 2 305 33
ushort 2 307 35
powerUpTime ms byte 1 309 37
usbFineResistor Resistor offset
(ohms = 0.05 + offset *
0.0001)
auxFineResistor Resistor offset
(ohms = 0.10 + offset *
0.0001)
sybte (signed) 1 310 38
sbyte (signed) 1 311 39
initialUsbVoltage See Table 6. ushort 2 312 40
initialAuxVoltage See Table 6. ushort 2 314 42
hardwareRevision Hardware revision level
(1=A, 2=B, 3=C, etc.)
byte 1 312 44
temperatureLimit Degrees Celsius byte 1 313 45
usbPassthroughMode 0=off, 1=on, 2=auto byte 1 314 46
mainCoarseResistor Resistor offset
(ohms = 0.05 + offset *
0.0001)
usbCoarseResistor Resistor offset
(ohms = 0.05 + offset *
0.0001)
auxCoarseResistor Resistor offset
(ohms = 0.10 + offset *
0.0001)
defMainFineResistor Default resistor offset
(ohms = 0.05 + offset *
0.0001)
defUsbFineResistor Default resistor offset
(ohms = 0.05 + offset *
0.0001)
defAuxFineResistor Default resistor offset
(ohms = 0.10 + offset *
0.0001)
defMainCoarseResistor Default resistor offset
(ohms = 0.05 + offset *
0.0001)
defUsbCoarseResistor Default resistor offset
(ohms = 0.05 + offset *
sbyte (signed) 1 315 47
sbyte (signed) 1 316 48
sbyte (signed) 1 317 49
sbyte (signed) 1 318 50
sbyte (signed) 1 319 51
sbyte (signed) 1 320 52
sbyte (signed) 1 321 53
sbyte (signed) 1 322 54

38
0.0001)
defAuxCoarseResistor Default resistor offset
(ohms = 0.10 + offset *
0.0001)
eventCode Event code:
0 = none
1 = USB connection lost
2 = too many dropped
samples
3 = reset requested by
host
eventData Supplementary event
data (interpretation
depends on eventCode)
sbyte (signed) 1 323 55
byte 1 324 56
ushort 2 325 57
checkSum Checksum byte byte 1 327 59
Total length 60
Table 4: Status packet layout
The file is then padded with zeros up until file offset 1024, where the sample data begins.
Interpreting the Sample Data
Beginning at offset 1024, sample data is recorded at a rate indicated in the Status Packet.
Each sample consists of up to four two-byte quantities, three of which are optional,
depending on the captureDataMask field at offset 158.
The total count of samples is given by the totalCount field of the header.
The four quantities are the current measurements for the Main, Usb, and/or Aux channels,
and a voltage for the channel indicated by the voltageIsAux bit of the leds field of the
Status packet (file offset 296). If the bit is set, the voltage is the Aux channel voltage,
otherwise it is the Main channel voltage.
The current measurements can each be either on the Fine or Coarse scale, independently of
each other, and the scale can change from one sample to the next. For fine scale
measurements each tick represents 1 uA (microamp), whereas for the coarse scale, each
tick represents 250 uA.
A coarse measurement always has the low-order bit set. For fine measurements, the loworder
bit is always clear. After determining the scale, the low-order bit should be cleared
before calculating the current.
For voltage, the two low-order bits are the two marker channels. The lowest bit is Marker
0, the next bit is Marker 1. These bits should be masked off before calculating voltage.
The layout of each sample is as follows:

39
Field C# Data
Type
Main Current short
(signed)
USB Current short
(signed)
Aux Current short
(signed)
Main or Aux
Voltage, and
Markers
ushort
(unsigned)
Bytes Tick value Present if:
2 1 uA (fine)
250 uA (coarse)
2 1 uA (fine)
250 uA (coarse)
2 1 uA (fine)
250 uA (coarse)
2 See Table 6 Always
Table 5: Sample layout
(captureDataMask &
0x1000) != 0
(captureDataMask &
0x2000) != 0
(captureDataMask &
0x4000) != 0
The following table lists the value of each voltage tick in microvolts (uV), depending on the
hardware revision level and the channel:
Hardware
Revision
Main USB Aux
A 62.5 uV / tick 62.5 uV / tick 62.5 uV / tick
B 125 uV / tick 125 uV / tick 62.5 uV / tick
C or later 125 uV / tick 125 uV / tick 125 uV / tick
Missing data values
Table 6: Voltage units
In order to account for the time gaps caused by calibration cycles, delays in communication
between the power monitor and the PC host, or other causes, the PowerTool software
inserts missing data indicators. For current measurements, missing data is recorded as
0x8001, while for voltage the missing value is 0xFFFF.
Should a missing value be encountered within a given sample, the entire sample should be
treated as missing, but the 200 us of time for the sample should be accounted for.
Example C# program to process a PT4 file
// ----------------------------------------------------
// This C# program reads and processes each sample in a
// PT4 file sequentially, from the first sample to the
// last.
//
// The name of the file to be processed is taken from

40
// the command line argument.
//
// Copyright (c) Monsoon Solutions, Inc.
// All Rights Reserved.
// ----------------------------------------------------
using System;
using System.IO;
using System.Diagnostics;
namespace SyncTest
{
public static class PT4
{
// fixed file offsets
public const long headerOffset = 0;
public const long statusOffset = 272;
public const long sampleOffset = 1024;
// bitmasks
private const short coarseMask = 1;
private const ushort marker0Mask = 1;
private const ushort marker1Mask = 2;
private const ushort markerMask = marker0Mask | marker1Mask;
// missing data indicators
const short missingRawCurrent = unchecked((short)0x8001);
const ushort missingRawVoltage = 0xffff;
// Enums for file header
public enum CalibrationStatus : int
{
OK, Failed
}
public enum VoutSetting : int
{
Typical, Low, High, Custom
}
[FlagsAttribute] // bitwise-maskable
public enum SelectField : int
{
None = 0x00,

41
}
Avg = 0x01,
Min = 0x02,
Max = 0x04,
Main = 0x08,
Usb = 0x10,
Aux = 0x20,
Marker = 0x40,
All = Avg | Min | Max
public enum RunMode : int
{
NoGUI, GUI
}
[FlagsAttribute] // bitwise-maskable
public enum CaptureMask : ushort
{
chanMain = 0x1000,
chanUsb = 0x2000,
chanAux = 0x4000,
chanMarker = 0x8000,
chanMask = 0xf000,
}
// File header structure
public struct Pt4Header
{
public int headSize;
public string name;
public int batterySize;
public DateTime captureDate;
public string serialNumber;
public CalibrationStatus calibrationStatus;
public VoutSetting voutSetting;
public float voutValue;
public int hardwareRate;
public float softwareRate; // ignore
public SelectField powerField;
public SelectField currentField;
public SelectField voltageField;
public string captureSetting;
public string swVersion;
public RunMode runMode;

42
}
public int exitCode;
public long totalCount;
public ushort statusOffset;
public ushort statusSize;
public ushort sampleOffset;
public ushort sampleSize;
public ushort initialMainVoltage;
public ushort initialUsbVoltage;
public ushort initialAuxVoltage;
public CaptureMask captureDataMask;
public ulong sampleCount;
public ulong missingCount;
public float avgMainVoltage;
public float avgMainCurrent;
public float avgMainPower;
public float avgUsbVoltage;
public float avgUsbCurrent;
public float avgUsbPower;
public float avgAuxVoltage;
public float avgAuxCurrent;
public float avgAuxPower;
static public void ReadHeader(BinaryReader reader,
ref Pt4Header header)
{
// remember original position
long oldPos = reader.BaseStream.Position;
// move to start of file
reader.BaseStream.Position = 0;
// read file header
header.headSize = reader.ReadInt32();
header.name = reader.ReadString().Trim();
header.batterySize = reader.ReadInt32();
header.captureDate =
DateTime.FromBinary(reader.ReadInt64());
header.serialNumber = reader.ReadString().Trim();
header.calibrationStatus =
(CalibrationStatus)reader.ReadInt32();
header.voutSetting = (VoutSetting)reader.ReadInt32();
header.voutValue = reader.ReadSingle();
header.hardwareRate = reader.ReadInt32();

43
}
header.softwareRate = (float)header.hardwareRate;
reader.ReadSingle(); // ignore software rate
header.powerField = (SelectField)reader.ReadInt32();
header.currentField = (SelectField)reader.ReadInt32();
header.voltageField = (SelectField)reader.ReadInt32();
header.captureSetting = reader.ReadString().Trim();
header.swVersion = reader.ReadString().Trim();
header.runMode = (RunMode)reader.ReadInt32();
header.exitCode = reader.ReadInt32();
header.totalCount = reader.ReadInt64();
header.statusOffset = reader.ReadUInt16();
header.statusSize = reader.ReadUInt16();
header.sampleOffset = reader.ReadUInt16();
header.sampleSize = reader.ReadUInt16();
header.initialMainVoltage = reader.ReadUInt16();
header.initialUsbVoltage = reader.ReadUInt16();
header.initialAuxVoltage = reader.ReadUInt16();
header.captureDataMask = (CaptureMask)reader.ReadUInt16();
header.sampleCount = reader.ReadUInt64();
header.missingCount = reader.ReadUInt64();
ulong count = Math.Max(1, header.sampleCount -
header.missingCount);
// convert sums to averages
header.avgMainVoltage = reader.ReadSingle() / count;
header.avgMainCurrent = reader.ReadSingle() / count;
header.avgMainPower = reader.ReadSingle() / count;
header.avgUsbVoltage = reader.ReadSingle() / count;
header.avgUsbCurrent = reader.ReadSingle() / count;
header.avgUsbPower = reader.ReadSingle() / count;
header.avgAuxVoltage = reader.ReadSingle() / count;
header.avgAuxCurrent = reader.ReadSingle() / count;
header.avgAuxPower = reader.ReadSingle() / count;
// restore original position
reader.BaseStream.Position = oldPos;
// Enums for status packet
public enum PacketType : byte
{
set = 1, start, stop,
status = 0x10, sample = 0x20

44
}
public struct Observation
{
public short mainCurrent;
public short usbCurrent;
public short auxCurrent;
public ushort voltage;
}
[FlagsAttribute]
public enum PmStatus : byte
{
unitNotAtVoltage = 0x01,
cannotPowerOutput = 0x02,
checksumError = 0x04,
followsLastSamplePacket = 0x08,
responseToStopPacket = 0x10,
responseToResetCommand = 0x20,
badPacketReceived = 0x40
}
[FlagsAttribute]
public enum Leds : byte
{
disableButtonPressed = 0x01,
errorLedOn = 0x02,
fanMotorOn = 0x04,
voltageIsAux = 0x08,
}
public enum HardwareRev : byte
{
revA = 1, revB, revC, revD
}
public enum UsbPassthroughMode : byte
{
off, on, auto, trigger, sync
}
public enum EventCode : byte
{
noEvent = 0,

45
}
usbConnectionLost,
tooManyDroppedObservations,
resetRequestedByHost
// Statuc packet structure
public struct StatusPacket
{
public byte packetLength;
public PacketType packetType;
public byte firmwareVersion;
public byte protocolVersion;
public Observation fineObs;
public Observation coarseObs;
public byte outputVoltageSetting;
public sbyte temperature;
public PmStatus pmStatus;
public byte reserved;
public Leds leds;
public sbyte mainFineResistorOffset;
public ushort serialNumber;
public byte sampleRate;
public ushort dacCalLow;
public ushort dacCalHigh;
public ushort powerupCurrentLimit;
public ushort runtimeCurrentLimit;
public byte powerupTime;
public sbyte usbFineResistorOffset;
public sbyte auxFineResistorOffset;
public ushort initialUsbVoltage;
public ushort initialAuxVoltage;
public HardwareRev hardwareRevision;
public byte temperatureLimit;
public UsbPassthroughMode usbPassthroughMode;
public sbyte mainCoarseResistorOffset;
public sbyte usbCoarseResistorOffset;
public sbyte auxCoarseResistorOffset;
public sbyte factoryMainFineResistorOffset;
public sbyte factoryUsbFineResistorOffset;
public sbyte factoryAuxFineResistorOffset;
public sbyte factoryMainCoarseResistorOffset;
public sbyte factoryUsbCoarseResistorOffset;
public sbyte factoryAuxCoarseResistorOffset;
public EventCode eventCode;

46
}
public ushort eventData;
public byte checksum;
static public void ReadStatusPacket(BinaryReader reader,
ref StatusPacket status)
{
// remember origibal position
long oldPos = reader.BaseStream.Position;
// move to start of status packet
reader.BaseStream.Position = statusOffset;
// read status packet
status.packetLength = reader.ReadByte();
status.packetType = (PacketType)reader.ReadByte();
Debug.Assert(status.packetType == PacketType.status);
status.firmwareVersion = reader.ReadByte();
status.protocolVersion = reader.ReadByte();
Debug.Assert(status.protocolVersion >= 16);
status.fineObs.mainCurrent = reader.ReadInt16();
status.fineObs.usbCurrent = reader.ReadInt16();
status.fineObs.auxCurrent = reader.ReadInt16();
status.fineObs.voltage = reader.ReadUInt16();
status.coarseObs.mainCurrent = reader.ReadInt16();
status.coarseObs.usbCurrent = reader.ReadInt16();
status.coarseObs.auxCurrent = reader.ReadInt16();
status.coarseObs.voltage = reader.ReadUInt16();
status.outputVoltageSetting = reader.ReadByte();
status.temperature = reader.ReadSByte();
status.pmStatus = (PmStatus)reader.ReadByte();
status.reserved = reader.ReadByte();
status.leds = (Leds)reader.ReadByte();
status.mainFineResistorOffset = reader.ReadSByte();
status.serialNumber = reader.ReadUInt16();
status.sampleRate = reader.ReadByte();
status.dacCalLow = reader.ReadUInt16();
status.dacCalHigh = reader.ReadUInt16();
status.powerupCurrentLimit = reader.ReadUInt16();
status.runtimeCurrentLimit = reader.ReadUInt16();
status.powerupTime = reader.ReadByte();
status.usbFineResistorOffset = reader.ReadSByte();
status.auxFineResistorOffset = reader.ReadSByte();
status.initialUsbVoltage = reader.ReadUInt16();

47
}
status.initialAuxVoltage = reader.ReadUInt16();
status.hardwareRevision = (HardwareRev)reader.ReadByte();
status.temperatureLimit = reader.ReadByte();
status.usbPassthroughMode =
(UsbPassthroughMode)reader.ReadByte();
status.mainCoarseResistorOffset = reader.ReadSByte();
status.usbCoarseResistorOffset = reader.ReadSByte();
status.auxCoarseResistorOffset = reader.ReadSByte();
status.factoryMainFineResistorOffset = reader.ReadSByte();
status.factoryUsbFineResistorOffset = reader.ReadSByte();
status.factoryAuxFineResistorOffset = reader.ReadSByte();
status.factoryMainCoarseResistorOffset =
reader.ReadSByte();
status.factoryUsbCoarseResistorOffset =
reader.ReadSByte();
status.factoryAuxCoarseResistorOffset =
reader.ReadSByte();
status.eventCode = (EventCode)reader.ReadByte();
status.eventData = reader.ReadUInt16();
status.checksum = reader.ReadByte();
// restore original position
reader.BaseStream.Position = oldPos;
static public long BytesPerSample(CaptureMask captureDataMask)
{
long result = sizeof(ushort); // voltage always present
}
if ((captureDataMask & CaptureMask.chanMain) != 0)
result += sizeof(short);
if ((captureDataMask & CaptureMask.chanUsb) != 0)
result += sizeof(short);
if ((captureDataMask & CaptureMask.chanAux) != 0)
result += sizeof(short);
return result;
static public long SamplePosition(long sampleIndex,
CaptureMask captureDataMask)
{

48
}
long result = sampleOffset +
BytesPerSample(captureDataMask) * sampleIndex;
return result;
static public long SamplePosition(double seconds,
CaptureMask captureDataMask,
ref StatusPacket statusPacket)
{
seconds = Math.Max(0, seconds);
}
long bytesPerSample = BytesPerSample(captureDataMask);
long freq = 1000 * statusPacket.sampleRate;
long result = (long)(seconds * freq * bytesPerSample);
long err = result % bytesPerSample;
if (err > 0) // must fall on boundary
result += (bytesPerSample - err);
result += sampleOffset;
return result;
static public long SampleCount(BinaryReader reader,
CaptureMask captureDataMask)
{
return (reader.BaseStream.Length - sampleOffset)
/ BytesPerSample(captureDataMask);
}
public struct Sample
{
public long sampleIndex; // 0...N-1
public double timeStamp; // fractional seconds
public bool mainPresent; // whether Main was recorded
public double mainCurrent; // current in milliamps
public double mainVoltage; // volts
public bool usbPresent; // whether Usb was recorded
public double usbCurrent; // current in milliamps
public double usbVoltage; // volts

49
}
public bool auxPresent; // whether Aux was recorded
public double auxCurrent; // current in milliamps
public double auxVoltage; // volts;
public bool markerPresent; // whether markers/voltages
// were recorded
public bool marker0; // Marker 0
public bool marker1; // Marker 1
public bool missing; // true if this sample was
// missing
static public void GetSample(long sampleIndex,
CaptureMask captureDataMask,
StatusPacket statusPacket,
BinaryReader reader,
ref Sample sample)
{
// remember the index and time
sample.sampleIndex = sampleIndex;
sample.timeStamp = sampleIndex
/ (1000.0 * statusPacket.sampleRate);
// intial settings for all flags
sample.mainPresent =
(captureDataMask & CaptureMask.chanMain) != 0;
sample.usbPresent =
(captureDataMask & CaptureMask.chanUsb) != 0;
sample.auxPresent =
(captureDataMask & CaptureMask.chanAux) != 0;
sample.markerPresent = true;
sample.missing = false;
// abort if no data was selected
long bytesPerSample = BytesPerSample(captureDataMask);
if (bytesPerSample == 0)
return;
// remember original position
long oldPos = reader.BaseStream.Position;
// position the file to the start of the desired sample
long newPos = SamplePosition(sampleIndex, captureDataMask);
if (oldPos != newPos)

50
reader.BaseStream.Position = newPos;
// get default voltages (V) for the three channels
sample.mainVoltage =
2.0 + statusPacket.outputVoltageSetting * 0.01;
sample.usbVoltage =
(double)statusPacket.initialUsbVoltage * 125 / 1e6f;
if (statusPacket.hardwareRevision < HardwareRev.revB)
sample.usbVoltage /= 2;
sample.auxVoltage =
(double)statusPacket.initialAuxVoltage * 125 / 1e6f;
if (statusPacket.hardwareRevision < HardwareRev.revC)
sample.auxVoltage /= 2;
// Main current (mA)
if (sample.mainPresent)
{
short raw = reader.ReadInt16();
}
sample.missing = sample.missing ||
raw == missingRawCurrent;
if (!sample.missing)
{
bool coarse = (raw & coarseMask) != 0;
raw &= ~coarseMask;
sample.mainCurrent = raw / 1000f; // uA -> mA
if (coarse)
sample.mainCurrent *= 250;
}
// Aux1 current (mA)
if (sample.usbPresent)
{
short raw = reader.ReadInt16();
sample.missing = sample.missing ||
raw == missingRawCurrent;
if (!sample.missing)
{
bool coarse = (raw & coarseMask) != 0;
raw &= ~coarseMask;

51
}
}
sample.usbCurrent = raw / 1000f; // uA -> mA
if (coarse)
sample.usbCurrent *= 250;
// Aux2 current (mA)
if (sample.auxPresent)
{
short raw = reader.ReadInt16();
}
sample.missing = sample.missing ||
raw == missingRawCurrent;
if (!sample.missing)
{
bool coarse = (raw & coarseMask) != 0;
raw &= ~coarseMask;
sample.auxCurrent = raw / 1000f; // uA -> mA
if (coarse)
sample.auxCurrent *= 250;
}
// Markers and Voltage (V)
{
ushort uraw = reader.ReadUInt16();
sample.missing = sample.missing ||
uraw == missingRawVoltage;
if (!sample.missing)
{
// strip out marker bits
sample.marker0 = (uraw & marker0Mask) != 0;
sample.marker1 = (uraw & marker1Mask) != 0;
uraw &= unchecked((ushort)~markerMask);
// calculate voltage
double voltage = (double)uraw * 125 / 1e6f;
// assign the high-res voltage, as appropriate
if ((statusPacket.leds & Leds.voltageIsAux) != 0)
{
sample.auxVoltage = voltage;
if (statusPacket.hardwareRevision

52
}
}
}
}
}
{
}
< HardwareRev.revC)
sample.auxVoltage /= 2;
else
{
sample.mainVoltage = voltage;
if (statusPacket.hardwareRevision
< HardwareRev.revB)
{
sample.mainVoltage /= 2;
}
}
// restore original position, if we moved it earlier
if (oldPos != newPos)
reader.BaseStream.Position = oldPos;
class Program
{
static void Main(string[] args)
{
// open the file named in the command line argument
string fileName = args[0];
if (!File.Exists(fileName))
return;
FileStream pt4Stream = File.Open(fileName,
FileMode.Open,
FileAccess.Read,
FileShare.ReadWrite);
BinaryReader pt4Reader = new BinaryReader(pt4Stream);
// reader the file header
PT4.Pt4Header header = new PT4.Pt4Header();
PT4.ReadHeader(pt4Reader, ref header);
// read the Status Packet
PT4.StatusPacket statusPacket = new PT4.StatusPacket();

53
}
}
}
PT4.ReadStatusPacket(pt4Reader, ref statusPacket);
// determine the number of samples in the file
long sampleCount = PT4.SampleCount(pt4Reader,
header.captureDataMask);
// pre-position input file to the beginning of the sample
// data (saves a lot of repositioning in the GetSample
// routine)
pt4Reader.BaseStream.Position = PT4.sampleOffset;
// process the samples sequentially, beginning to end
PT4.Sample sample = new PT4.Sample();
for (long sampleIndex = 0;
sampleIndex < sampleCount;
sampleIndex++)
{
// read the next sample
PT4.GetSample(sampleIndex, header.captureDataMask,
statusPacket, pt4Reader, ref sample);
}
// process the sample
Console.WriteLine("#{0} {1} sec {2} mA {3} V",
sampleIndex,
sample.timeStamp,
sample.mainCurrent,
sample.mainVoltage);
// close input file
pt4Reader.Close();