Argent Data Systems OpenTracker USB User manual

Argent Data Systems
OpenTracker USB
User’s Manual
Revised 2-25-2013
Argent Data Systems, Inc.
PO Bo 579
Santa Maria, CA 93456-0579
USA
[phone] / [phone]
Fa [phone]
www.argentdata.com
Copyright © 2007-2013 Argent Data Systems
All Rights Reserved
APRS
®
is a registered trademark of Bob Bruninga, WB4APR

OpenTracker USB User’s Manual
1. Introduction .............................................................................................................. 1
2. Major Features.......................................................................................................... 1
3. Hardware Description............................................................................................. 3
3.1. SERIAL Connector Pin Assi nments ............................................................ 3
3.2. RADIO Connector Pin Assi nments............................................................. 3
3.3. Internal Header CN4 ....................................................................................... 3
4. Jumper Settin s ........................................................................................................ 4
5. Setup and Confi uration......................................................................................... 5
5.1. USB Operation.................................................................................................. 5
6. Position Modes ......................................................................................................... 6
7. Port Modes ................................................................................................................ 6
AUTO............................................................................................................................. 6
KISS ................................................................................................................................ 7
WS2300 .......................................................................................................................... 7
DAVIS............................................................................................................................ 7
FLOW............................................................................................................................. 7
8. Remote Access .......................................................................................................... 8
9. Safe Mode.................................................................................................................. 8
10. Authentication.................................................................................................... 10
11. OTWINCFG Confi uration Pro ram.............................................................. 11
11.1. Overwritin an Invalid Confi uration ................................................... 11
11.2. Turbo Mode ................................................................................................ 11
11.3. Auto-detect ports ....................................................................................... 11
11.4. Warm Boot vs. Cold Boot.......................................................................... 12
11.5. Workin Offline ......................................................................................... 12
11.6. Main Confi uration Window................................................................... 12
11.7. Confi uration Profiles ............................................................................... 13
11.8. Loadin and Savin Settin s.................................................................... 13
11.9. Basic Confi uration Options .................................................................... 13
11.10. Tunin and Dia nostics ............................................................................ 19
11.11. Access List................................................................................................... 20
11.12. Profile Switchin ........................................................................................ 20
12. Command Reference ......................................................................................... 22
13. Telemetry............................................................................................................. 33
14. Script System ...................................................................................................... 34
14.1. Script Editor ................................................................................................ 34
14.2. Script Commands....................................................................................... 36
14.3. Counters ...................................................................................................... 38
15. UI-View32 Setup ................................................................................................ 40

OpenTracker USB User’s Manual 1
1. Introduction
The OpenTracker USB was desi ned as a low-cost entry-level APRS tracker, but
it includes features previously found only on si nificantly more expensive
models.
The OpenTracker USB includes almost all of the features of the hi her-end
Tracker2, with the exception of the di ipeater and Garmin protocol functions.
Firmware updates and enhancements are published frequently, so check our
website at http://www.ar entdata.com/support to make sure you have the latest
firmware and documentation. The Wiki site at http://wiki.ar entdata.com also
has in-depth technical information and user-contributed tips and tricks.
2. Major Features
APRS Tracker - The OpenTracker USB is first and foremost a full-featured APRS
tracker. It works with GPS receivers usin the industry-standard NMEA format
($GPRMC, $GPGGA, and $GPGLL sentences). In addition to transmittin its
own position, it can also decode incomin positions and plot them as waypoints
on the screen of a GPS receiver, selectin appropriate symbols and settin
comment text and other waypoint details if supported by the receiver.
KISS Mode - The KISS protocol defines an interface between a TNC and its host,
typically a PC. This mode allows the tracker to be used with PC-based APRS
pro rams like Xastir, WinAPRS, and UI-View32. It can also be used with non-
APRS applications, subject to the limitations of the tracker’s transmit and receive
buffers.
Weather Station – The OpenTracker USB can be connected to several models of
weather station, includin the Peet Bros. Ultimeter 2000 series, Dallas/AAG 1-
Wire Weather Station, Davis Vanta ePro 2, and LaCrosse WS-2310 wireless
weather station, to provide remote weather telemetry.
Command Console – While the OpenTracker USB comes with a Windows-based
confi uration pro ram, it can also be confi ured, tuned, and up raded throu h a
traditional console interface with command syntax similar to that of the classic
TNC2 and its clones. Keyboard-to-keyboard QSOs are supported throu h a
‘converse’ mode as well as APRS messa in commands.

OpenTracker USB User’s Manual 2
Telemetry – The OpenTracker USB has on-board temperature and volta e
sensors, plus four analo 0-20v inputs and two di ital input/output pins.
Temperature and volta e readin s can be reported in status packets, and the
other readin s can be reported in an APRS telemetry messa e.
Scripting – To automate a variety of tasks and increase the device’s feature set,
the OpenTracker USB includes a simple user-pro rammable script system.

OpenTracker USB User’s Manual 3
3. Hardware Description
3.1. S RIAL Connector Pin Assignments
2: Data in (port A)
3: Data out (port A)
4: Power output for GPS
5: Ground
7: Data out (port B)
8: Data in (port B)
Note: The serial interface is confi ured as DTE (data terminal equipment) to
allow direct connection to a GPS receiver. Connection to a PC requires a null-
modem cable.
3.2. RADIO Connector Pin Assignments
1: Audio out
2: COR / Squelch input
3: PTT out
5: Audio in
6: Ground
7: Power in (7 to 24 volts)
8: PTT in
9: AUX IO / GPIO1 / Power relay output
3.3. Internal Header CN4
1: +5 Volt power
2: 1-Wire data bus
3: Analo input 1
4: Analo input 2
5: Analo input 3
6: Analo input 4
7: Di ital input/output
8: Ground

OpenTracker USB User’s Manual 4
4. Jumper Settings
Three settin s are controlled by the jumper block on the circuit board.
‘HI’ – This jumper sets the audio output level to the hi h ran e. This is needed
mostly for mobile radios, especially some commercial models.
‘HT’ – Selects if push-to-talk si nalin throu h the audio output line is enabled.
Use this jumper with most HTs by Icom, Yaesu, and Alinco handhelds, but not
Kenwood, Puxin , and Baofen .
‘Vout’ – Selects GPS output volta e on pin 4 of the serial connector. This is set to
5v by default. Valid positions are horizontal for 5v and vertical to pass the
OTUSB’s unre ulated supply volta e (typically 12v) strai ht throu h to pin 4.
Use the 5v settin for all GPS receivers supplied by Ar ent Data Systems.
If you don’t expect to use a 12-volt GPS receiver, clippin the pin marked ‘12’ is
hi hly recommended to eliminate the possibility of accidentally settin the
jumper to the wron position and destroyin the GPS receiver.

OpenTracker USB User’s Manual 5
sudo modprobe
usbserial vendor=0x134a product=0x9000
5. Setup and Configuration
You can use a PC to connect to the OpenTracker USB usin either the Windows
confi uration pro ram (otwincf .exe) or a terminal emulation pro ram of your
choice, such as HyperTerminal, PuTTY, or Minicom. Either the serial port or the
USB port may be used for confi uration.
To use the command console, connect at the proper baud rate (4800 baud is the
default) and press enter several times until you see a command prompt. To use
the Windows confi uration pro ram, simply start the pro ram, select the COM
port, and power up the device.
The only settin absolutely required for normal APRS tracker operation is the
callsi n. The defaults for all other settin s should be reasonable, but you should
check on locally recommended settin s, particularly for the di ipeater path.
5.1. USB Operation
The USB port can be used for confi urin the tracker with the otwincf .exe
utility, accessin the command prompt, and connectin to a PC in KISS interface
mode.
When the USB connection is in use, the tracker draws its power from the host
system - no other connections are required for confi uration of the unit.
Note that the OpenTracker USB does NOT act as a host device - the USB port is
only used for connectin to a PC, and cannot be used to connect a USB GPS
receiver.
Windows systems require the provided .INF for the OpenTracker USB to be
reco nized properly. Once installed, you can find the COM port number
assi ned in Device Mana er. Alternatively, you can plu in the USB port after
runnin otwincf .exe and the new port should be detected automatically.
Modern Linux distributions should automatically assi n a device name like
/dev/ttyACM0 to the OpenTracker USB. If the unit is not automatically
reco nized, you can select the driver with the followin command:

OpenTracker USB User’s Manual 6
Mac OS X should assi n a device name startin with /dev/cu.usbmodem.
Other modern operatin systems should be able to use the OpenTracker USB as a
eneric CDC ACM serial device. Its VID is 0x134A and PID is 0x9000.
6. Position Modes
Before ettin started, it’s important to understand that the tracker ordinarily
will not make automatic transmissions (includin position, status, weather, and
telemetry packets) unless it knows where it is.
The device knows where it is when it receives a valid fix from a GPS receiver, or
when it’s pro rammed by the user with a fixed position. It can be confi ured to
transmit without a valid fix; if no fix has been received since power-up, only
status and telemetry packets will be sent. If the last valid GPS fix is more than 30
seconds old, a ‘NO FIX’ warnin is added to each position packet.
If the AUTOSAVE option is enabled, as soon as the last valid fix is 30 seconds old,
that position is saved and the device enters fixed position mode. As soon as
another valid fix is received, it switches back to GPS mode. This is useful for
portable weather stations that will have a GPS receiver connected only briefly
durin deployment.
7. Port Modes
The OpenTracker USB has two serial ports that share the same physical
connector. A ‘Y’ adapter is available to separate the ports if needed. Both ports
can operate in multiple modes:
AUTO – In this mode, the device will automatically detect NMEA GPS data, Peet
Bros weather data, or (for port A only) command console input. Note that while
both ports can be confi ured in AUTO mode, only one should be used for a
iven function at any time. For example, port A can accept NMEA data while
port B accepts weather data, but providin NMEA data to both ports
simultaneously will cause unpredictable operation.
If the USB port is not in KISS mode, the command console will only be present
on the USB port while it’s connected. When the USB port is disconnected, the
console will default back to port A.

OpenTracker USB User’s Manual 7
KISS – In KISS mode, a PC or other host device sends and receives raw AX.25
packets. Keep in mind that even with one or both ports in KISS mode, the
tracker will continue to perform its other functions, includin messa in and
remote command access. The host should use a different callsi n/SSID
combination to avoid interference.
WS2300 – Supports LaCrosse WS-2300 series weather stations at 2400 baud,
a ain i norin manual baud rate settin s.
DAVIS – Supports Davis Vanta e Pro series weather stations.
T XT – Functions like ‘converse’ mode. Each line of text is sent as a plain text
packet when a carria e return is received. Pressin control-C twice will exit
TEXT mode.
FLOW – Valid only for port B, this settin causes the port B pins to function as
CTS/RTS flow control si nals for port A.
The USB port has two modes, controlled by the ‘USB KISS’ option in
otwincf .exe or the USBKISS ON/OFF option from the command console.
When USBKISS is ON, the USB port will operate in KISS mode. If the tracker
receives a KISS exit command from the host, USBKISS will be switched OFF.
With USBKISS OFF, the USB port functions as the command console. In both
modes, the baud rate settin has no effect on the serial link’s speed. Some
applications may make assumptions about timin based on the selected speed,
however, so it’s recommended that the baud rate be set to 115,200 bps or hi her.

OpenTracker USB User’s Manual 8
8. Remote Access
Commands can be issued to the tracker remotely via APRS messa es. The
ori inatin station’s callsi n must appear in the device’s security authorization
list (see AUTHLIST command.) Commands are prefixed with ‘ CMD ’, and the
results of the command, if any, will be send back as an APRS messa e to the
sendin station.
For example, ‘ CMD VERSION ’, sent from an APRS client, will cause the tar et
device to reply with its firmware version.
In response to a RESET command, the device will attempt to send one
acknowled ement before resettin . This is intended to prevent messa e retries
from causin multiple resets, but especially if the channel is busy there is a
possibility that the acknowled ement will not be sent before the reset is
executed. A RESET command should be cancelled after a few retries with no
response received to check if the device has indeed been reset.
9. Safe Mode
Startin with firmware build 56294, the OpenTracker USB includes a 'safe mode'
option to place the device temporarily into its default confi uration. The safe
mode entry condition is checked only when the tracker first powers on or resets.
It should always be possible to recover from an invalid confi uration usin a
cold boot procedure over the serial interface. This procedure, however, can be
problematic with certain hardware setups. Safe mode offers an alternative to a
serial cold boot.
Safe mode is entered by connectin the di ital I/O and 1-Wire bus pins (CN4 pins
7 and 2) to ether. Connect the pins with a short piece of wire or other
conductive item such as a pair of metal tweezers while the tracker powers up.
The tracker will blink its red LED five times to indicate safe mode entry and will
display *SAFE MODE* in the banner.
While in safe mode, the tracker will operate from a saved copy of the default
confi uration, with ports A and B set to AUTO at 4800 baud. Chan es to the
confi uration will affect the normal confi uration and not the saved defaults. To

OpenTracker USB User’s Manual 9
exit safe mode, use the RESET command or power off the tracker after removin
the jumper used to enter safe mode.
The use of the default confi uration is temporary. Normal operation will be
resumed when safe mode is exited. To overwrite the active confi uration with
the saved defaults, use the RESET DEFAULT command. The tracker need not be
in safe mode to restore defaults.

OpenTracker USB User’s Manual 10
10. Authentication
In addition to the security authorization list, remote access to the tracker can be
controlled throu h a more secure one-time password mechanism. This
mechanism is enabled by settin PWAUTH ON .
To set up one-time password authentication, use the command SECRET followed
by a pass phrase of at least 16 characters. The device will use this pass phrase to
enerate a 128-bit key that is stored in nonvolatile memory. The password
sequence counter is set to 0 when the key is created.
The PASSLIST command can then be used to enerate a list of 4-character one-time
passwords, each listed with a unique sequence number. These passwords must
be used in the specified order. You can print out this list and cross off each
password as it’s used.
To use a password, append it to the CMD prefix at the start of the command
messa e. For example, if the next valid password is ‘SBCY’, the messa e
“ CMDSBCY VERSION ” will execute the VERSION command.
While it should be virtually impossible for someone to determine the next
password without knowin your pass phrase, the system is not foolproof. Be
sure not to use the same pass phrase on two different devices, because an
eavesdropper who hears a password used on one device (or who retrieves an old
messa e from an online database) could potentially use the same password on
the other unit.
Also, should a valid password be sent without bein received by the tar et
device, an eavesdropper would know the next valid password. If you are unsure
of bein able to reach the tar et device, send an unauthenticated messa e or
query first and make sure you et a reply.
cmd:secret The quick brown fox umps over the lazy dog.
Set.
cmd:passlist 24
0:C0EP 1:U60T 2:8JES 3:BVBN 4:Z2ZC 5:TEAR 6:VA5S 7:EV1F
8:JCBX 9:NE8G 10:NAAM 11:P1Y8 12:ZJ59 13:H654 14:KSBB 15:PDM8
16:VM89 17:GTNW 18:CW52 19:B7ZX 20:X4DF 21:Z5HF 22:CNNU 23:A8FS

OpenTracker USB User’s Manual 11
11. OTWINCFG Configuration Program
The OpenTracker USB can be confi ured usin the otwincf .exe pro ram under
Windows. The pro ram is available for download at
http://www.ar entdata.com/support.
Connect the tracker and start the confi uration pro ram. The first window
displayed allows you to select the COM port that the tracker is connected to.
11.1. Overwriting an Invalid Configuration
The ‘Erase device and load new firmware’ option will load a new firmware
ima e, usin the default confi uration settin s, without attemptin to read the
existin confi uration first. This is particularly useful if the tracker has an invalid
or missin confi uration.
11.2. Turbo Mode
By default, the confi uration pro ram will attempt to connect at 115,200 baud. If
you have trouble connectin , use the ‘Disable Turbo’ option to force the pro ram
to connect at 19,200 baud.
11.3. Auto-detect ports
Selectin this option will cause the pro ram to constantly scan all of the ports
and display which are available. Connectin the tracker via USB while this
option is checked will cause the pro ram to automatically connect. On some
systems this option may cause trouble connectin ; disable it if you experience
problems.

OpenTracker USB User’s Manual 12
11.4. Warm Boot vs. Cold Boot
If the unit is already powered on and operatin when you click the ‘Connect’
button, the pro ram attempts a ‘warm boot’ operation to put the device into
confi uration mode. If the firmware has been corrupted, i.e. by a failed up rade,
it may fail to enter confi uration mode. You can correct this by performin a
‘cold boot’ - power the unit off and power it on a ain after clickin ‘Connect’.
11.5. Working Offline
If you need to edit a confi uration without connectin the tracker, click the
‘Offline’ button. You will need to have a saved confi uration file to work from.
11.6. Main Configuration Window

OpenTracker USB User’s Manual 13
11.7. Configuration Profiles
The OpenTracker USB can store two separate confi uration profiles. The profile
currently bein shown is selected usin the tabs at the top of the window labeled
‘Profile 1’ and ‘Profile 2’.
When it is first powered on, the tracker will always start out usin Profile 1.
After startup, profile selection depends on the settin s in the profile switchin
screen. To access these settin s, click ‘Profile Switchin ’. See the section below
on profile switch for more information.
11.8. Loading and Saving Settings
After chan in any confi uration options, you must click the ‘Write’ button to
write the chan es to the tracker’s firmware. You may also use the ‘Save to File’
button to save the confi uration options to a file, which can be loaded later usin
the ‘Load from File’ button.
11.9. Basic Configuration Options
Callsign – The radio callsi n to use when transmittin . Tactical callsi ns may be
used, but FCC and ITU rules require periodic identification. If the actual callsi n
is not used here, be sure to include it in the comment field.
Baud Rate – For normal VHF operation this should be 1200. 300 baud is
commonly used for HF. The mark and space frequencies are 1600 and 1800 hz
respectively in 300 baud mode.
Path – This specifies the di ipeater path to use. Specific callsi ns may be entered
(e. ., ‘K6SYV-10, K6TZ-10’) but for APRS operation a set of common aliases are
usually used. A su ested default path is ‘WIDE1-1, WIDE2-1’. It is rarely
necessary to use a path reater than WIDE3-3 (requestin three ‘wide’ di ipeater
hops), and excessive paths enerate lar e amounts of traffic that de rade the
performance of the network. If you’re not sure what path should be used for
your local area, check with a local di ipeater operator. This field may be left
blank.
Alternate Paths - When enabled, this option causes the tracker to alternate
between the paths specified in either profile with each transmission.

OpenTracker USB User’s Manual 14
Symbol Table and Symbol Code – These settin s control the symbol used to
indicate the station’s position when drawn on a map. See Appendix B for a
listin of available symbols.
Temp. Adjust – Calibration offset for onboard temperature sensor. The sensor
used on the OpenTracker is fairly linear across its operatin ran e and requires a
sin le-point calibration. The easiest way to accomplish this is to set a
thermometer next to the tracker. Subtract the temperature reported by the tracker
from the temperature shown by the thermometer, and enter that value in this
field. For example, if the thermometer shows the temperature as 26°C and the
tracker reports 29°C, enter –3 for the adjustment value.
Quiet Time – This settin determines how lon the channel must be clear before
the tracker will transmit. Each unit is approximately 1/56 second. Settin the
quiet time to zero causes the tracker to i nore detected traffic.
Text – This is a freeform text field. Anythin entered here will be displayed in
the comment portion of the transmission or in a separate status packet, as
selected. Keep comments as brief as possible to avoid wastin channel capacity,
or use the ‘Every __ Transmissions’ option to reduce how often the text is sent.
Altitude, Course/Speed, Time – When checked, report these values as indicated
by the GPS receiver. The timestamp may be in Days/Hours/Minutes or
Hours/Minutes/Seconds.
DAO – Enables the proposed !DAO! APRS extension to provide the map datum
used and an extra di it of latitude and lon itude resolution. May not be
supported by all APRS clients. The datum is always reported as WGS84, which
is the standard for normal APRS operation.
GPS Quality – Report number of satellites in use and horizontal dilution of
precision information as reported by the GPS receiver.
Temperature – Report temperature as indicated by the onboard temperature
sensor in the comment field, in de rees C. Not affected by the Metric / En lish
settin .

OpenTracker USB User’s Manual 15
Voltage – Report input volta e in the comment field. The maximum value is 18.5
volts, and the minimum is the dropout volta e of the re ulator – typically 6.7
volts.
Compressed – Enables Base91 compressed position reportin . This mode is
widely, but not universally, supported. Packets in Base91 format are shorter
than their uncompressed equivalents and provide reater position resolution.
Telemetry every n – Sends a telemetry packet every n transmissions. See the
telemetry section for more details.
TX Interval – How often the tracker should transmit. Allowable values are 0 to
65,535 seconds. This settin will depend on your intended use. One transmission
every two minutes is acceptable for most mobile stations. A fixed station (e. ., a
solar powered site reportin battery volta e and temperature) mi ht choose an
interval in the ran e of 5 to 30 minutes. If you require transmissions more often
than every two minutes or so, consider usin the SmartBeaconin ™ options
detailed below. Special events with many trackers and short transmission
intervals should be operated on a separate frequency, not on the shared APRS
channel. An interval of zero will disable timed transmissions.
SmartBeaconing – Ori inally developed for the HamHUD by Tony Arnerich,
KD7TA, and Steve Bra , KA9MVA, the SmartBeaconin ™ al orithm allows the
tracker to operate more efficiently by chan in how often it transmits dependin
on its speed and direction of travel.
When stopped or movin at a speed below the low speed settin , the tracker will
transmit at a fixed rate determined by the lower rate settin . Above the specified
hi h-speed threshold, the hi her rate settin is used. Between these two
extremes, the interval varies between the low and hi h rates dependin on the
speed. A turn an le can also be specified to cause the tracker to transmit when
turnin . The final settin ensures that the tracker will never transmit more often
than the specified interval, re ardless of speed and turn rate. This can be useful
to avoid transmittin more than once in a lon , shallow turn.

OpenTracker USB User’s Manual 16
Use PTT Input – When this checkbox is enabled, the tracker can be connected
inline with a microphone to operate in burst-after-voice (mic encoder) mode. A
packet will be transmitted whenever the microphone PTT is released.
Timeslot – The timeslot option is typically used to coordinate multiple trackers,
especially for special events where many transmitters will be sharin the same
channel with a hi h beacon rate. The number entered selects the timeslot’s offset,
in seconds, from the start of the hour. The tracker will transmit at this time, and
every transmit interval after that. The timeslot value should be smaller than the
transmit interval.
As an example, two trackers could be confi ured with an interval of 10 seconds,
with one tracker set to slot 0 and the other to slot 5. The first tracker would
transmit at 12:00:00, 12:00:10, 12:00:20, and so on, while the second would
transmit at 12:00:05, 12:00:15, and 12:00:20.
Position – The tracker can operate in GPS or fixed position mode. When
enterin a fixed position, enter de rees in the first box and decimal minutes in
the next box. Click on the buttons next to the coordinates to select North/South
and East/West.
Don’t require GPS fix – Normally, while in GPS mode, the tracker will not
transmit without a valid fix. When this option is selected, the tracker will
continue to transmit its last known position if GPS lock is lost for more than 30
seconds. This condition is indicated by the text ‘NOFIX’ in the status messa e. If
the tracker has received no valid fix since startup, no position will be reported.
Status text and telemetry packets will be unaffected. This option is particularly
useful for applications like hi h altitude balloons that may lose GPS lock after
landin , but still need to transmit to be found.

OpenTracker USB User’s Manual 17
Save – When enabled, the tracker will save its last-known GPS position as a
permanent fixed position if the GPS fix is lost. This may be used in the case of a
temporary weather station where a GPS receiver is installed only durin setup
and is removed to conserve power. The system must remain powered on for 30
seconds after GPS fix loss before the position is saved.
Waypoint Output – Enablin the waypoint output option causes the tracker to
parse received APRS positions and output them over the serial port at 4800 baud.
Waypoints are provided in both NMEA 0183 format ($GPWPL sentence) and
Ma ellan format ($PMGNWPL sentence).
Length Limit – Some GPS receivers are not capable of display the full 9
characters required for APRS call si ns and object names. Settin this option to a
smaller number causes the tracker to intelli ently truncate the name of the
waypoint. Spaces and dashes are eliminated first, and if further truncation is
required, characters are dropped from the left first. This prevents stations with
different SSIDs from conflictin – for example, with a limit of 6 characters,
KB6YUO-12 and KB6YUO-6 would be truncated as 6YUO12 and B6YUO6
respectively.
Use Custom Symbols - Enables the use of custom symbols if they have been
uploaded to a compatible Garmin GPS receiver (usin the Garmin xIma e
utility).
Range Limit - When enabled, waypoints will only be created for stations and
objects within the specified ran e.
nable Counter – This checkbox enables the di ital counter function. When this
function is enabled, the tracker will no lon er transmit immediately when X1 pin
4 is shorted to round. Instead, it will increment a counter and include the
current count in the status text, e. ., ‘CNT00001’. The maximum count is 65535,
after which the counter rolls over to zero. This option can not be used
concurrently with profile switchin with the ‘jumper’ option.
Reset on Transmit – Settin this checkbox causes the counter to reset with every
transmission. Hence, the count reported is the number of events since the last
transmission.

OpenTracker USB User’s Manual 18
Debounce – This is a delay applied to the counter input. After a counter event is
re istered, all subsequent events are i nored until the specified time has elapsed.
Without a suitable debounce settin , a typical pushbutton could re ister several
events for one press.
Power Control – When selected, the tracker will activate its power control line
(AUX IO) before each transmission. The tracker will pause for the specified
number of seconds to ive the transmitter time to power up. The power control
feature is especially useful for solar-powered weather or telemetry stations.
TX Audio Level – This slider sets the audio output level. This level can be set
interactively from the Tunin /Dia nostics screen. If you find that the required
level is less than one quarter of the full scale, make sure you have the ‘HI’ jumper
removed. Runnin with the audio level set in software to a very low level can
increase DAC quantization noise.
TX Delay – All radios require a certain amount of time to stabilize on their
transmittin frequency, and receivers also require time to lock on. This value
specifies the number of milliseconds the tracker should wait after the start of the
transmission before it be ins sendin data. Allowable values are 0 to 1023
milliseconds. Settin this value too hi h will keep the channel busy lon er than
necessary. Settin it too low will prevent packets from bein transmitted
properly. Findin the optimum value for your radio may require some
experimentation.
Don’t transmit if supply < n – To avoid over-dischar in batteries, enable this
option and enter the minimum volta e at which the tracker should operate the
transmitter.
Invert Carrier Detect – Usually used with mobile radios, this checkbox indicates
that the channel is busy when the carrier detect input is low.
Software DCD – This option selects the data carrier detect (DCD) mode used.
When unchecked, the tracker considers the channel to be busy in the presence of
any noise, includin voice or static. When checked, the channel is considered
busy only when a valid 1200 baud si nal is present.