OTWINCFG Configuration Guide

OTWINCFG is the Windows-based configuration program for all models of OpenTracker, OpenTracker+, and Tracker2. It can be downloaded here.

Many of the functions are common to all versions. Some are specific to a particular model, and may be disabled or not present if you're using a different model.

Connecting

The connection dialog appears when OTWINCFG is started.

Make sure you've selected the serial port that your tracker is connected to.

The most reliable way to connect to the tracker is to make sure the tracker is off before starting OTWINCFG, and to only connect power after clicking 'Connect'. If the tracker is already running, OTWINCFG will attempt to reset it and enter configuration mode, but this isn't always possible depending on the tracker's configuration.

If you experience write errors or other problems while configuring the tracker, try setting the 'Disable Turbo' option. This limits the connection speed to 4800 baud; some cables (in particular, programming cables for the RTrak and the internal serial cabling in the DR-135T) have trouble with the high speed that OTWINCFG uses by default.

To reload the firmware and completely discard the configuration, check 'Erase device and load new firmware'. This option is useful in the unusual event that the tracker configuration becomes corrupted.

To work with a saved configuration file offline, click 'Offline' and select the configuration file.

Main Screen

Two independent configuration profiles can be created for a tracker. The tabs at the top of the screen indicate which profile is currently being edited. Which profile is used by the tracker depends on the settings in the 'Profile Switching' screen.

Firmware Build

The firmware build number indicates the version of the firmware currently loaded on the tracker. Build numbers typically reflect the date (in modified Julian day format) of release.

Callsign

This is the radio callsign to be transmitted by the tracker. A tactical callsign can be used, but FCC and ITU rules require periodic identification. If the actual callsign of the licensee is not used here, be sure to include it in the comment field.

The callsign can include up to six alphanumeric characters, and optionally a dash (-) followed by a number from 1 to 15 called the SSID. Specific SSID numbers once had meanings assigned to them (e.g., -11 for a balloon), but this convention is unnecessary today.

Baud Rate

1200 baud is the standard for VHF APRS. 300 baud is generally used only on the HF bands, and never on the public VHF network.

Path

The path setting is a list of up to three callsigns or aliases that determine the routing of the packets sent on the air by the tracker. Entries are separated by commas. Do not enter spaces in this field. Leave the field blank to use no path. Good amateur practice should be observed. Keep paths to the minimum for your needs.

Proper path settings vary by country or region. For a detailed analysis, see this discussion. Some examples are:

• WIDE1-1,WIDE2-1 – New Paradigm mobile path. Requests 1st hop from all digipeaters, including fill-ins. Requests 2nd hop from WIDEn-N digipeaters.
• WIDE1-1 – Mobile path requesting a single hop from all New Paradigm digipeaters.
• SSn-N – Regional path (e.g., NCA2-1 or SCA1-1).
• WIDE2-1 – One hop from WIDEn-N digipeaters. Courteous for fixed stations.
• WIDE2-2 – Two hops. For fixed stations needing two hops.
• WIDE3-3 – Three hops. Discouraged unless necessary.
• RFONLY – Prevent IGates from passing the packet to the Internet.

Warnings: - RELAY, WIDE, TRACE, TRACEn-N, and SS are obsolete - Never use WIDE1-1 beyond the first hop - Never use WIDE1-2 or higher N - Never use anything other than WIDEn-N on a balloon or aircraft

Alternate Paths

Alternates between paths in Profile 1 and Profile 2.

Symbol Selection

The symbol table and code determine how the tracker appears on a map. See SYMBOLS.HTM and here.

Symbol	Description
#	Digipeater
'	Small aircraft
-	House
<	Motorcycle
>	Car
R	RV
[	Runner (or simply a person)
b	Bike
j	Jeep
k	Truck
v	Van
_	WX

Temp Adjust

The internal temperature sensor in some trackers requires a calibration offset for accurate readings. Enter the offset in this field — a positive number to add to the sensor value, or a negative number to subtract from it.

Quiet Time

Determines how long the channel must be clear before the tracker transmits. Each unit is approximately 1/56 second. Setting it to zero disables the receive LED and may affect traffic detection.

Text

Freeform text field shown in the comment or status packet. Keep brief to avoid wasting channel bandwidth. Use the 'Every __ Transmissions' option to reduce frequency.

Reporting Options

These settings control what extra data the tracker transmits. Keep packets short for reliability.

Altitude

Reports GPS-provided altitude, though it may be inaccurate by 100–200 feet.

DAO

Enables the !DAO! APRS extension for higher precision and datum (always WGS84).

Course/Speed

Enables course and speed reporting.

Time

Adds DHM or HMS timestamps. Usually not needed, as receiving clients timestamp packets.

GPS Quality

Adds HDOP and satellite count. Garmin protocol gives estimated position error (EPE).

Temperature

Reports temperature in Celsius (or optionally Fahrenheit on Tracker2).

Voltage

Reports supply voltage (not supported on T2-135).

Compressed

Enables Base91 compressed format for shorter, higher-resolution packets.

Telemetry

Controls how often telemetry packets are sent.

Transmission Control

Settings affecting when the tracker transmits.

TX Every...

How often to transmit (0–65535 sec). Adjust based on use. Frequent transmissions are discouraged. Use SmartBeaconing™ for dynamic control.

Skip ... if heard

(Tracker2 only) Skips transmissions if the tracker hears its own packet via digipeater.

Use SmartBeaconing

SmartBeaconing™ adapts beaconing to speed and movement for more efficient usage. Defaults are courteous — avoid abuse that causes excess beacons.

Use PTT Input

Enables mic-encoder mode; sends a packet after PTT release.

Enable Timeslotting

Used to coordinate multiple trackers. Offset in seconds from the hour. For example: - Tracker A: interval 10 sec, slot 0 → 12:00:00, 12:00:10... - Tracker B: interval 10 sec, slot 5 → 12:00:05, 12:00:15...

Half-second slots can be used as .5.

Position

Settings related to position source.

GPS / Fixed

'GPS' gets data from a receiver. 'Fixed' uses user-entered coordinates.

Save

(Tracker2 only) Saves last known GPS fix to flash when fix is older than 30 seconds.

Coordinate Entry

Enter latitude/longitude in degrees and decimal minutes (e.g., 34 45.56). Click N/S, E/W to set hemisphere.

Don't Require GPS fix

Allows transmission without GPS fix. Adds NO FIX warning.

Waypoint Output

Controls waypoints sent to mapping GPS receivers.

Waypoint Enable

Enables waypoint output.

Character Limit

Truncates names to receiver-compatible length. Drops characters from start.

Use Custom Symbols

(Tracker2 only) Enables custom APRS symbol set for Garmin GPSes using xImage utility.

Limit to ...

(Tracker2 only) Sets range limit for waypoints.

Serial Ports

(Tracker2 only) Two serial ports (A and B), independently configured.

Auto

Auto selects between console, NMEA, Peet Bros.

Garmin

Garmin binary mode (e.g., nuvi, StreetPilot).

KISS

KISS mode for PC apps (UI-View32, Xastir).

WS2300

LaCrosse WS23xx weather mode.

Flow

(Port B only, not on T2-135) disables Port B, uses for flow control of A.

Text

Transparent mode (in development).

Davis

Davis VantagePro weather station mode.

Autobaud

Automatically detects baud rate (may fail sometimes).

Counter

Some trackers have digital counter input. Adds CNT00001 in status text. Can reset with each transmission.

Power Control

Useful for solar/weather stations. Tracker can power on the radio before TX. Delay is configurable. 'Active low' reverses the signal.

Radio Interface

Most important setting is TX audio level. 3.2 kHz deviation is typical. 'HI' jumper increases range. Keep slider in upper half to minimize quantization noise.

More info: Setting RX/TX Levels

Troubleshooting

Upon clicking 'connect', OTWINCFG sends reset to tracker. Tracker should reset and enter bootloader. If it doesn't, reset it manually (power off/on). OTWINCFG cycles through modes/baud rates to connect.

Common issues:

• Wrong connections – All models except T2-135 require null modem (TX/RX crossed). T2-135 uses straight-through.
• No power – Tracker needs external power.
• Wrong COM port – Verify especially with USB adapters.
• Bad USB adapter – Use FTDI or Prolific-based adapters.
• Dead tracker – Should blink LED on power. If not, check manual.
• Deaf tracker – Early models can suffer static damage. Tracker resets, but doesn’t respond.

Write/config errors may be caused by: - Bad cables - Loose connections - Excessive crosstalk

Try different cables or the 'Disable Turbo' option to reduce baud rate.