Argent Data Systems Tracker4 User manual

Tracker4
APRS Tracker / TNC / Gateway
MANUAL
Version 1.02 Revised 8-2-2018

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Table of Contents
Introduction . . . . . . . . . . . 1
Hardware Description . . . . . 2
Interfaces . . . . . . . . . . . . . 2
Radio Interface (Rear DE9 Female). . . . . . 2
USB . . . . . . . . . . . . . . . . . . . . . . . . 3
Serial Port . . . . . . . . . . . . . . . . . . . . 3
RS-485 / Modbus RTU . . . . . . . . . . . . . 3
Setup. . . . . . . . . . . . . . . . 4
Callsign . . . . . . . . . . . . . . . . . . . . . . 4
Push-to-talk method . . . . . . . . . . . . . . 4
Audio levels . . . . . . . . . . . . . . . . . . . 5
WiFi Setup . . . . . . . . . . . . . 6
Accessing the Console. . . . . . 6
Alternative Setup Method . . . 7
Web Interface. . . . . . . . . . . 8
Home Screen. . . . . . . . . . . . . . . . . . . 9
Settings . . . . . . . . . . . . . . . . . . . . . .10
File System . . . . . . . . . . . . . . . . . . . .10
Info . . . . . . . . . . . . . . . . . . . . . . . .10
Introduction to APRS . . . . . .11
Command Reference . . . . . .13
APRS Commands . . . . . . . . . . . . . . . .15
Radio Commands . . . . . . . . . . . . . . . .15
Network Commands . . . . . . . . . . . . . .17
Debugging / Diagnostics . . . . . . . . . . 20
Configuration Parameters . . 22
Resetting to Defaults . . . . . 25
Logging . . . . . . . . . . . . . 25
Firmware Updates . . . . . . . 25
Disassembly . . . . . . . . . . 26
Application Setup . . . . . . . 27
APRSdroid . . . . . . . . . . . . . . . . . . . 27
APRSISCE/32 . . . . . . . . . . . . . . . . . . 28
FCC Part 15 Notice . . . . . . . 29
Warranty . . . . . . . . . . . . 30

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Introduction
The Tracker4 is the successor to the OpenTracker, Tracker2, and Tracker3 series of tracker/TNC
devices. It includes all of the major features of its predecessors and adds many more. Features
include:
• Internal GPS receiver
• WiFi network support (802.11b/g/n)
• Standalone IGate support (no PC required)
• Simple browser-based configuration
• Telnet server for remote access
• BASIC interpreter for powerful scripting
• RS-485 interface with Modbus RTU support
• DTMF encoding and decoding
• WAV file playback
• 24 MB of internal file storage for data logging, scripts, etc.
Preliminary Documentation
This is the first public release of the Tracker4 and this manual. Please check www.argentdata.
com frequently for documentation and firmware updates for the latest information, feature
enhancements, and bug fixes.

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Hardware Description
The Tracker4 measures 5.1” by 3.3” by 1.2”, including its mounting flange. Its front panel has a
male DE9 connector for RS-232 serial accessories such as weather stations, a 10-position 0.150”
pitch pluggable terminal block with connections for power, RS-485, Dallas 1-Wire, and three
analog inputs, and activity indicator LEDs.
The rear panel includes a 2.1x5.5mm center-positive DC power jack for power input in the range
of 6 to 24 volts, a female DE9 connector for interfacing with a radio, a reverse-polarity SMA
connector for the WiFi antenna (included), and a regular SMA connect for the GPS antenna (also
included).
Interfaces
Interfaces are provided on various connectors on the front and rear panels of the tracker.
Radio Interface (Rear DE9 Female)
1Audio out (to radio) 5Audio in (from radio)
2Unused 6Ground
3Push-to-talk (PTT) output 7Power in (optional)
4Unused 8Unused
These pinouts are compatible with all prior Argent models using DE9 radio connectors, as well as
other common TNCs including the Kantronics KPC-3+. If the power input isn’t used by your tracker
cable, ensure that the cable does not have that pin shorted to ground.
The PTT mode must be set appropriately for the radio being used. Most base station and
mobile radios use a separate PTT input. Many handheld radios, with the notable exception of
most Kenwood models, combine the microphone and PTT signals. For combined PTT models, the
‘HT PTT’ option must be enabled in the configuration.

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USB
The USB mini-B connector is the primary way you’ll connect the tracker to a PC. The tracker
enumerates as a composite device with both mass storage device (MSD) and communications
device class (CDC) functions. The MSD function provides access to the tracker’s internal file
system, and the CDC function allows console and KISS access through a virtual serial port.
For Mac OS X, Linux, and Windows 10, no drivers or INF files are required. For Windows versions
prior to 10, an INF file (included on the tracker’s own drive) is required for the CDC function.
Windows 8 users will need to boot with driver signing turned off to install the INF file.
On Mac OS X and Linux, the CDC serial port will typically show up as /dev/ttyACM0 if no other
CDC ACM devices are present. On Windows, you can check under ‘Ports’ in Device Manager to
find the COM port number assigned to the tracker by Windows.
The CDC serial port defaults to console mode. You can access the console using a terminal
program like PuTTY or Minicom. The baud rate setting is ignored. You should see a banner and
command prompt immediately upon opening the connection.
If KISS packets are detected on the CDC serial port, the port will enter KISS mode automatically.
This eliminates the need to manually configure the tracker for KISS operation. To exit KISS mode,
enter control-C several times until the command prompt appears.
Serial Port
The front panel male DE9 connector is an RS-232 serial port that supports baud rates up to
921600 baud. Currently the serial port is used only for weather station interfacing.
RS-485 / Modbus RTU
An RS-485 serial port is provided on the front panel terminal block. RS-485 is a long-range
multi-drop serial interface with good noise immunity. Modbus RTU is a widely-used protocol for
interfacing with devices such as sensors and relays.

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Setup
Before your Tracker4 is put into operation, some setup is required. Start by connecting the WiFi
antenna, GPS antenna, and a power source. The tracker may be powered through the rear DC
jack (a wall adapter may be purchased separately), the radio interface connector, the front
terminal block, or via USB.
Once the tracker is powered up, the initial configuration can be done through the web interface
or the command console. Both methods are detailed in their corresponding sections below.
Regardless of the method used, a few parameters need to be set.
Callsign
A callsign must be set before many of the tracker’s functions will operate. This callsign will usually
be the legal radio callsign of the tracker’s operator. A secondary station identifier (SSID) may be
used to distinguish multiple trackers with the same callsign. The SSID follows the callsign after a
dash and is a number from 0 to 15. The default SSID is 0, which is not displayed. For example, two
trackers operating under the callsign W1AW could be set with SSIDs of 1 and 2, which would be
represented as W1AW-1 and W1AW-2. W1AW alone is equivalent to W1AW-0.
Identification laws vary by country, but in most cases the callsign field is not required to be a legal
callsign as long as appropriate identification is provided somewhere and sent at appropriate
intervals. A common example is a tracker with a tactical callsign, for example ‘ROVER-1’, with the
legal callsign being reported in the comment field.
Setting the tracker’s callsign is not required for KISS mode. The KISS packets sent by the host
application will include their own callsign fields. The callsign must be set for the tracker to work in
standalone IGate mode, however, because gated packets include the gateway’s callsign.
Push-to-talk method
Some handheld radios don’t have a separate push-to-talk line and instead combine it with
the mic audio. For these radios, the HT PTT option must be enabled. See the radio interfacing
section of this manual for details

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Audio levels
Proper audio levels are critical for reliable transmitting (TX) and receiving (RX) of data packets.
For normal APRS operation, the tracker’s RX audio level setting isn’t critical - you can leave it set
at its maximum. For certain voice features you’ll need to adjust it to match the peak audio level
coming from the radio. If the radio doesn’t have a fixed level audio output, make sure you set
its volume such that the level does not exceed the tracker’s maximum of 3 volts peak-to-peak or
clipping will occur and degrade receive performance.
The TX audio level setting is particularly important. Failure to set the TX audio level properly is the
most common cause of readability problems. The correct level setting will depend on your radio.
Setting the level too low will result in a weak signal that’s easily lost in noise. Setting it too high will
cause distortion that will render packets difficult or impossible to decode.
For typical APRS operation on the 2-meter band, a proper TX audio level setting is one that results
in an FM deviation of about 3.0 to 3.5 kHz. Ideally this should be set with a service monitor or
deviation meter. If you don’t have equipment to measure the deviation directly, use another radio
to listen to the tracker’s transmitted packets. Start low and increase the TX audio level setting
until the apparent loudness doesn’t increase anymore, and then back it off by 10-20%.
Status LEDs
Two LEDs on the front panel provide various status indications. The TX/RX LED lights red when
transmitting and green when receiving. ACT blinks green when a valid GPS fix is received or red if
the fix is invalid.
File System
The tracker’s file system can be used for storing scripts, logs, and voice announcements, among
other things. Approximately 24 MB of storage space is available. The file system is used for
temporary storage of downloaded updates, but otherwise its contents are not needed for normal
operation of the device - the file system can be wiped and reformatted at any time without
affecting operation, as the firmware and configuration data are stored outside of this file area.

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WiFi Setup
To access the tracker’s web interface or use any of its network-related features, you’ll first need
to configure its network settings. Out of the box, the tracker is configured to create a WiFi Direct
group named ‘Tracker4’. If you have a WiFi Direct-capable device like an Android phone or
tablet, select ‘WiFi Direct’ from the WiFi network menu and you should see the tracker in the list of
available networks.
For devices that don’t support WiFi Direct, the tracker will also appear as a conventional WiFi
access point with a prefix beginning with ‘DIRECT-’. The default password is ‘password’.
Once you’re connected to the tracker’s network, you can access its web configuration interface
at <http://192.168.100.1>. From there, you can reconfigure the WiFi system as desired. For a fixed
installation with an existing WiFi network, in most cases you’ll want to enter your network’s SSID
and password. When it’s rebooted, the tracker will then connect to the specified network.
If the ‘create network’ option is set, the tracker will fall back to creating its own network in WiFi
Direct or Access Point mode, depending on settings, if no known network is available. This can
be used to switch between independent operation, for example in a moving vehicle, and fixed
location operation.
Accessing the Console
The Tracker4 features an improved version of the command shell found on earlier Tracker2 and
Tracker3 series devices. At present, the console is accessible only through USB and not the front
panel serial port.
When connected to a PC, the tracker will appear as both a mass storage device, like a USB flash
drive, and a virtual serial port. Linux, Mac OS X, and Windows 10 should all work without any
special configuration or drivers. On Linux and Mac, the serial device will typically appear as /dev/
ttyACM0 if it’s the first such device connected. On Windows, access the device manager (press
Windows-X and select Device Manager) and check under ‘Ports (COM & LPT)’ to find the COM
port number assigned to the tracker.

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Windows versions prior to 10 require an INF file that tells the operating system what driver to load.
This INF file is included on the tracker’s own file system, and it can also be downloaded from
argentdata.com. Please note that Windows 8 must have driver signing disabled first.
Once the virtual serial port is available, you can use a terminal program like PuTTY or Minicom to
access the tracker’s command console. The baud rate setting is ignored.
After opening the connection you should see the Tracker4 banner message and a cmd: prompt.
For a list of commands, enter ‘help’ or ‘?’.
Settings can be viewed and set using the ‘show’ and ‘set’ commands. Enter ‘show’ alone to list all
settings. Note that some settings are also accessible through their own commands for the sake
of consistency and compatibility with earlier Argent trackers and also with TNC2 style devices.
For example, ‘MYCALL’ is equivalent to ‘show aprs_callsign’ and ‘MYCALL W1AW’ is equivalent to
‘set aprs_callsign w1aw’.
The tracker accepts many familiar MS-DOS style commands like ‘dir’, ‘type’, and ‘move’. It also
accepts their Unix-style equivalents like ‘ls’, ‘cat’, and ‘mv’. Keep in mind that the tracker’s
shell is not POSIX-compliant and these commands may not behave exactly like the similarly
named POSIX or DOS commands. Take particular care when moving or deleting files and using
wildcards.
Alternative Setup Method
If you are unable to set up the tracker using either WiFi or the serial console, you can also
configure the tracker by placing shell commands in a file called ‘autoexec.cmd’ in the tracker’s
root directory. Enter one command per line. The commands are executed in sequence as if they
had been entered at the command prompt every time the tracker is powered up.

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Web Interface
The tracker’s web interface contains its own help system and is generally fairly self-explanatory,
but there are a few things to be aware of. In Google Chrome, it should look something like this:
There are a number of status icons that may appear on the right side of the title bar. These are:
No GPS lock
Connection to tracker lost
KISS interface is active
Watchdog timer error
The icon will appear at startup, but should disappear as soon as the GPS receiver gets a valid
fix. Make sure the GPS antenna has a clear view of the sky.
indicates that the web app has lost contact with the tracker. The network may be down, or