A GPS tracking system for marinas, boat rentals, and other watercraft

Raveon’s asset tracking solutions gives customers the ability to focus on keeping up with their assets, instead of keeping up with monthly fees. Using radio transmissions to broadcast received GPS messages, Raveon’s GPS transponders allow a marina operator to track all of their rental boats or other watercraft in real-time using a graphical display. Competing GSM (cellular based) systems charge monthly data usage fees to transmit your GPS tracking information through their cellular telephone signal towers, and only function where you have cell phone service.

If you can’t make a cell phone call, likely, you can’t be tracked. Instead of getting the oars out when you lose cell service, the RavTrack real-time tracking system provides a complete standalone system. No usage fees or third party infrastructure is necessary; instead RavTrack GPS transponders operate via VHF or UHF digital radio transmissions, providing you with instant status updates on every rental boat or other watercraft in your fleet.

Raveon’s easily configured and customizable GPS tracking system is designed to operate where and how you want it to operate, including a specialty line of weatherproof IP65 rated GPS transponders perfect for small watercraft such as jet-skis, kayaks, or the like.

On the boat, the Raveon GPS transponder simply requires access to the 12 volt (DC) power source, that’s likely already a part of your rental boat, an antenna for the radio, and an antenna for the GPS. With available power saving modes, Raveon’s data radios will only draw a small fraction of power, meaning that it’s even suitable for a sailboat!

Raveon also offers compact design options suitable for jet skis (UHF systems suggested for Jet Skis for more compact sized antennas.) Once your transponder is installed in your boat just turn it on and go. The transponder will immediately begin searching for GPS lock and will begin broadcasting its location automatically at your chosen intervals.

The powerful GPS transponders broadcast position signals that can easily be received several miles over open water. At your marina, truck, or your general base of operations, another transponder and antenna receives the incoming GPS reports from the boat or rental fleet. View the Port Asset Tracking infographic to learn more about how the RavTrack system is designed. For more information, learn how the Port of Long Beach partnered with Ravtrack for their tracking needs.

GPS Tracking Software

Raveon’s Windows based RavTrackPC program is available to provide you with a platform to view your assets (As seen in the image on the right.) Customization integrated into RavTrackPC will provide your tracking system with the map you want to use. You will be able to see the locations and IDs of each of your tracked boats out on the water on your map. You can also configure RavTrackPC with rules and alerts so that if your boat starts moving at 2 AM or simply hasn’t reported in several minutes an alarm will be triggered. Alarms can do anything from making a loud noise, to sending an email, tweet or SMS message, to triggering a third party program on your system through a command line interface.

RavTrackPC does far more than just tracking movement too, it can be used to track speed, duration and proximity to other tracked objects as well! RavTrackPC provides Geo-Fence alerts, where you can create invisible borders to alert you when a boat is not where it’s supposed to be, or when it is heading back in to the marina or launch ramp. This greatly facilitates dock service not to mention how much easier it is catch your daredevil kids/clients in the act of doing 40mph in a no-wake zone in your boat! It also keeps the harbor master happy. Furthermore, if the people in any of your rental craft have an issue, the optionally installed boat assistance switch can be triggered and help can be dispatched directly to the distressed boat’s location.

Displaying GPS Position

The RavTrack GPS transponder can also be set up to be displayed on many on-board GPS systems for boats or vehicles. (Such as the Lowrance HDS-5 and Garmin 400 seen in the images on the left.) This means that not only can you track your boat from the marina, it means that your boat or tow vehicle can also track yourboats! No more awkwardly waiting around at the loading/unloading ramps! You can watch your boat approach from anywhere, long before it’s in eyesight range. This is also very useful for the private yacht operator in keeping track of tender boats or tracking recreational watercraft. Not only is RavTrack great for keeping marina staff updated, the mobile tracking capabilities of RavTrack are ideal for use in your service or rescue craft. Furthermore, if your rental boat has a compatible display, your marina dock location can appear on the display to guide the lost helmsman back home.

Raveon’s GPS tracking solutions provide a service that’s simple to use as well as appropriate for an enjoyable boating experience while eliminating the stress of uncertainty. Whether that means the peace of mind of knowing your customers whereabouts, or simply knowing your boat/fleet will be where you parked it last, Raveon’s stand alone, recurring-fee free, real time tracking will help improve your overall customer service, safety, and fleet maintenance.

Give us a call to discuss your particular operation and allow us to customize a GPS tracking solution tailored to what you need from your GPS tracking system, including system planning, custom radio configurations, or other special needs. If you have questions about the RavTrack GPS tracking system, we also offer an informative webinar.

August 29, 2013August 29, 2013

GPS Antenna Selection

The selection of a proper GPS antenna for a GPS tracking system is very important. The main criteria to keep in mind when choosing a GPS antenna to work with your Raveon M7 series GPS transponder is:

Amplified. The antenna must have a build in RF amplifier that will operate off of 3.3V DC. The power for the GPS antenna’s RF amplifier is feed down the center-conductor of the coax-cable going to the antenna.
SMA connector. The RF connector for the GPS antenna is an SMA type connector. The cable will have a male connector on it, and the M7 has the female.
Proper Mount. GPS antennas are available in many different mounting configurations.
Proper Environment. Some antennas are designed to be mounted on the roof of a car, others are suitable in salt-water environment and others are not. Consult the manufacturer for information on temperature range and environmental restrictions.

Raveon offers a number of GPS antennas for mobile GPS tracking. They are shown on the website here:
http://ravtrack.com/gps-antenna-choices

The simplest GPS antenna for vehicle mounting is Raveon’s RV-AN-GP2:

universal active gps antenna installation

Talley Electronics (http://www.talleycom.com/ ) distributes many different GPS antennas, and if you wish to order them from Raveon with your M7 transponder, please just add it to your order, and we will include it with your shipment.

Talley’s GPS antennas are in their on-line catalog here: http://www.talleycom.com/store/category.jsp?cat=311&clr=1

The MobileMark SM-1575-2C-WHT-180 GPS antenna is a rugged sealed amplified antenna suitable for most any application, even those with harsh environments.

January 12, 2011January 19, 2011

Antenna Tuning or Cutting

Selecting and installing a proper antenna for a telemetry radio, GPS transponder, or base station involves selecting a suitable style of antenna for your installation, properly mounting the antenna, cabling the antenna to the radio connection, and possibly adding a lightning arrestor to the antenna cable. One of the most important considerations is ensuring you select an antenna that works well for your operating frequency. In many cases this involves tuning the antenna for the proper frequency.

Any antenna is constructed of a metal conducting element. Often this element is insulated from direct contact with a rubber or fiberglass sheath, or some other material and you will not see the metal element itself. In any good antenna the shape and length of the element was carefully considered when the antenna was designed. Some elements are simple straight thin metal rods, others are coils, loops or other styles or combinations. Frequently the antenna is built to work at a very specific frequency or range of frequencies, such as 450-460MHz. If you select an antenna built for the wrong frequency you will have very poor results.

Some common antennas allow for the user to adjust the antenna for their frequency. The antenna may be built to cover a wide range of frequencies, such as 400-500MHz, but should be adjusted to the precise user frequency. As radio transmissions are actually radio “waves” you may remember that a radio frequency and radio wavelength are tightly related. Tuning an antenna typically involves adjusting the length of the conducting element(s) to be a specific ratio of the actual radio wavelength.

Often field tunable antennas involve 2 elements that are allowed to slide or telescope back and forth to achieve a specific antenna length. In other cases the element(s) may need to be physically cut or altered to a specific length. In the case of a common omni-directional fiberglass antenna the metal element(s) are housed within a fiberglass insulative sheath, and must be removed from the sheath to gain access. Here the user must expose the metal conductive element(s) and cut them to the proper length. If the antenna has multiple elements , each element may require a different cut and re-assembly must place them in proper order.

To physically cut the element(s) a good metal file, Dremel tool, or fine tooth metal saw may be used to cut the element(s), or score and snap them carefully. Once done the element(s) go back into the fiberglass sheath in correct order. You can smooth any sharp points first if you like.

If an antenna is meant to be tunable it will come with a chart or other instructions as to what length is intended for a specific frequency, and perhaps instructions on how to physically perform the cut or adjustment. If you intend to cut-to-tune your antenna remember these 5 key points:

Never cut an antenna unless you are certain you need to do so.
Make sure you have clear instructions on how to measure and cut the antenna for your frequency, and measure very carefully.
If the antenna contains multiple elements, plan and track each element with individual care.
Wear eye protection and follow any safety procedures.
Never cut the element too short. It may be better to take it increments at a time to achieve proper length.

If you order an antenna from us that requires cutting, we are happy to do this for you prior to shipping if you can tell us the precise frequency you need.

December 17, 2010

The RavTrack Atlas PL personal GPS locator radio network capabilities

Most people will identify the Atlas PL personal locator as an excellent device for people to wear and to send GPS position information, alerts, and man-down status. Typically the Atlas PL is used in conjunction with the RavTrack AVL GPS vehicle transponders which are equipped in fleet vehicles and used for base receiving stations as well as store-and-forward repeaters. It is common for these latter transponders to be used to complete a GPS tracking radio network for tracking both personnel, and vehicles, or other costly assets.

However, it is also possible for the Atlas PL units alone to be used to construct a GPS tracking network complete with multiple base stations and/or a repeater, without the involvement of the vehicle transponder models in the system. The Atlas PL inherently has all the capabilities of the vehicle based models. Releasing these capabilities is simply a matter of following correct configuration procedures for the Atlas PL.

The following diagram demonstrates the use of the Atlas PL in its traditional role as a personal GPS transponder but also as multiple base stations, with one base station also serving as a repeater.

Within each box are typical settings of the Atlas PL as part of the GPS tracking scheme. Above each box are the intended uses of each Atlas PL in the tracking network, while below each box are a series of configuration commands the user should issue to each Atlas PL unit to configure each unit for the particular use specified. Finally, alongside each command is an indication of what that command actually configures in the Atlas PL.

Each Atlas PL starts out in GPS mode 8. This configures the Atlas PL to function in the most common transponder configuration and enables the advanced battery management functions of the Atlas PL as well. However, it is important to note that the command GPS – such as GPS 8 – is a macro command which configures many different aspects of the unit. Most commonly the GPS command is understood by the user to set the format of the NMEA output, but it in fact does much more. For instance, issuing the command “GPS 8” to an Atlas PL will completely turn off the receiver circuitry of the unit. This is not what we need for a base station receiver or repeater. The subsequent commands change other configurable attributes of the Atlas PL, overriding the macro set of configuration parameters, to arrive at the final desired configuration. It is critical these configuration commands be issued after the GPS command.

We hope this demonstrates some of the capabilities of the Atlas PL not commonly identified by the end user. Should you have in mind a specific function of an Atlas PL that is not apparent, we encourage you to contact us.

December 3, 2010August 4, 2011

Fast GPS reporting with TDMA timeslots

RavTrack is very fast at reporting the positions of even large fleets over a single radio channel because each RavTrack transponder is assigned a specific time slot in which to transmit, avoiding interference which may occur if multiple devices were permitted to transmit simultaneously. The fact that all transponders share a “common clock” via the GPS satellite signals allows us to assign a unique timeslot to each device, yet maintain timing coordination over a large fleet of devices.

RavTrack timeslots are built on 50 millisecond increments by factory default, athough 10msec granularity can be achieved with newer firmware versions. For the purposes of illustration we will assume each time slot must be a multiple of 50msec. The specific size of your time slot is typically determined by the bandwidth/transmission rate of your particular transponder and the presence or absence of a repeater.

Most FCC licenses granted in the USA are for narrowband (12.5KHz) channel spacing. The associated RavTrack transponders operate quite well at 4800 baud transmission rate (factory default), although slower rates can be used. These transponders can complete a position report transmission in about 64msec, so a 100msec timeslot would be the factory default when no repeater is in the system. If your license permits wideband (25KHz) channel spacing, and your transponders are capable of wideband operation, the factory default transmission rate is 9600 baud. In this instance a position transmission can be completed in about 32msec, so a 50msec timeslot is typically used when no repeater is in the system.

If your system uses a store-and-forward repeater you need to make each timeslot longer so that once a vehicle reports, the repeater has sufficient time to receive, process, and repeat the transmission on “quiet air” before the next vehicle transmission occurs. In a 9600 baud system a 100msec timeslot may be used if you are not encrypting your transmissions, but with encryption a 150msec time slot should be used, as the repeater needs a bit more time to process an encrypted message than an unencrypted message. In a 4800 baud system using a repeater a 200msec timeslot may be used whether or not you are encrypting the position transmissions.

Timeslots are numbered starting at zero, and the zero time slot is reserved by the system. Thus you can start numbering your transponder time slots at slot 1 (0001). In a system using 100msec timeslots the first second is completed once time slots 0 through 9 are used (10 time slots total). For this reason, up to 9 vehicle transmissions can be completed in the first second, and in this example your fleet size would be limited to a total of 9 vehicles if you need the entire fleet to report each second. As the reserved zero time slot only occurs at the start of any particular TDMA cycle, cycles longer than 1 second would allow the addition of 10 more time 100msec slots for each second added to the cycle. Thus a fleet using 100msec time slots can provide reports from 19 vehicles every 2 seconds, 29 vehicles every 3 seconds, and so forth. Similar logic applies to other RavTrack timing schemes.

If your fleet is quite large and you want faster updates than the 100msec timeslot scheme allows, you can double your fleet size if local regulations allow you to use wideband transmissions that yield a 50msec time slot. In many deployemnets a fleet can scale much larger and still preserve fast report cycles simply by using multiple frequencies. As transponders on different frequencies will not interfere with one another even if transmitting simultaneously, a properly architected system using five frequencies can report five times faster than the same system using only one frequency.

When setting up your fleet timing it is a good idea to leave a little extra capacity in your timing scheme to allow the easy addition of new vehicles to the fleet.

Finally, if you want to use the RavTrack transponders to transmit not only position data, but extra data as well (e.g. from an on-board telemetry device), you will need longer time slots to send this extra data. Please contact us in this regard, and we are happy to help you in architecting a solid system.

For a more technical programming perspective on TDMA time slots as used by RavTrack see the following articles: http://ravtrack.com/GPStracking/tdma-transmission-overview/361/

http://ravtrack.com/GPStracking/tdma-time-slots/71/

or consult your technical manual.

October 6, 2010

COCOM GPS Tracking Limits

The U.S. Department of Commerce requires that all exportable GPS products contain performance limitations so that they cannot be used in a manner that could threaten the security of the United States. The following limitations are implemented on the Trimble Copernicus receiver receiver.

Immediate access to satellite measurements and navigation results is disabled when the receiver’s velocity is computed to be greater than 1000 knots, or its altitude is computed to be above 18,000 meters. The receiver continuously resets until the COCOM situation is cleared.

If the Raveon GPS transponder will be used in aviation applications, the unit should be put into the AIR mode. See the posting “gps-receiver-dynamics” for information about the AIR, LAND< and SEA modes.

September 30, 2010April 17, 2012

GPS Receiver Dynamics

The GPS receiver in Raveon’s M7 and Atlas PL GPS transponder may be configured for different situations. By default it is configured for LAND operation.
Selecting the correct operating parameters has a significant impact on GPS receiver performance. GPS receiver dynamics may be optimized for LAND, AIR, or SEA operation.

LAND = 1    Maximum speed the GPS will receive at is 233knots/268mph/430kmh. Useful altitude from -2000 to +9000 meters.
SEA = 2    Maximum speed the GPS will receive is not specified. Useful altitude from -2000 to +9000 meters.
AIR = 3   Maximum speed the GPS will receive at is 1000knots/1150mph/1800kmh. Useful altitude from -2000 to +50,000 meters.

The default setting for the GPS receiver used in Raveon’s M7 series of GPS transponders and Atlas PL Transponders is LAND.
The default LAND operating parameters allow the receiver to perform well in most environments. Transponders with firmware version C12 or higher are able to view the GPS receiver’s configured dynamics, and change the dynamic mode between AIR, LAND, and SEA. Upon power up, the firmware reads the internal GPS receiver’s current configuration.

The user can optimize the internal GPS receiver in the transponder to a particular application. If the receiver is then taken out of this environment, the specifically tuned receiver may not operate as well as a receiver with the default options.
The dynamics feature default setting is LAND mode, where the receiver assumes a moderate dynamic environment. In this case, the satellite search and re-acquisition routines are optimized for vehicle type environments. In SEA mode, the search and re-acquisition routines assume a low acceleration environment. In AIR mode, the search and reacquisition routines are optimized for high acceleration conditions.

Reading the GPS Receiver Configuration

The GPS receiver configuration may be determined by using the GX command to show the overall configuration of the M7 or Atlas PL transponder. The “Dynamics” command will also return a string in the following format that indicates how the GPS receiver in the transponder is currently configured.

MMM, EE.E, SS.S

MMM: dynamic mode AIR, LAND, or SEA
EE.E: Elevation Mask
SS.S: Signal Mask

Elevation Mask

This is the minimum elevation angle for satellites to be used in a solution output by the receiver. Satellites which are near the horizon are typically more difficult to track due to signal attenuation, and are also generally less accurate due to higher variability in the ionospheric and tropospheric corruption of the signal. When there are no obstructions, the receiver can generally track a satellite down to near the horizon.

Signal Mask

This mask defines the minimum signal strength for a satellite used in a solution. There is some internal hysteresis on this threshold which allows brief excursions below the threshold if lock is maintained and the signal was previously above the mask.

Configuring the Dynamics

Use the DYNAMICS command to set or read the dynamics. DYNAMICS with no parameter will return the configuration. The following commands may be used to set the dynamics:

DYNAMICS 0    (factory default dynamic mode)
DYNAMICS 1    (LAND)
DYNAMICS 2    (SEA)
DYNAMICS 3    (AIR)

When issuing the DYNAMICS x command, give the GPS receiver a few seconds to execute it. The M7’s firmware will also send a “flash save” command to the GPS receiver after the dynamics configuration is changed so that the change becomes permanent in the GPS receiver. Upon power-up, the GPS receiver will use the new dyncamics setting.

To verify the dynamics setting was saved, cycle power on the M7 or Atlas PL, enter the CONFIG mode, and enter the GX command to view the overall configuration of the device. The GPS receiver dynamics will be displayed.

Advanced GPS Receiver Configuration

To facilitate the advanced user, Raveon added a command “PASS” in the C12 firmware. PASS will pass the parameter of the command to the internal GPS receiver in NMEA format. The GPS receiver used in the M7 transponder and ATLAS PL personal locator is a Trimble Copernicus II. The technical manual for the Copernicus II contains details on how to configure it using NMEA type messages.

For example, to set the GPS receiver to AIR mode, issue the following command while in the command mode.
PASS $PTNLSCR,0.60,5.00,12.00,6.00,0.0000020,0,3,1

The command’s paramter is a NMEA formatted sentence without the * or the checksum. The M7 or Atlas will append the * and the checksum to the sentence before sending it to the internal GPS receiver. To set the dynamics, use the DYNAMICS x command, not the PASS command. The PASS command is provided to the advanced user who wished to reconfigure the receiver’s low-level configiruation paramters such as signal and elevation masks.

If you change the GPS receiver’s configuration with the PASS command, do not forget to issue the save configuration command to the GPS reciever. The save command for the GPS receiver in the M7 and ATLAS PL is:
PASS $PTNLSRT,H,2,7,0

August 24, 2010January 16, 2011

Connecting M7 to Garmin Oregon

Overview

The M7 GX series of GPS transponders may be directly connected to a Garmin Oregon 450. When connected, the Garmin display map will show the location of the vehicle it is in PLUS the location of all other M7 transponders within radio range. This unique feature allows one to quickly, easily, and inexpensively, make a mobile AVL system for tracking cars, trucks, race cars, construction equipment, or any thing Raveon’s M7 GX transponder may be installed on.

The Garmin Oregon 450 has a built-in interfaces for a “NMEA 0183? devices, which is another way of saying that they can connect to other devices using a serial cable. The NMEA 0183 is an RS232 serial connection that typically operates at 4800 baud. It is used to exchange way point and other information between displays, GPS devices, and transponders.

When Raveon’s M7 GX transponder is connected to the Oregon using the NMEA 0183 connection, the M7 transponder can put icons on the screen of the Garmin display. As the transponder received updated positions from other vehicles, it updates the position of the icons on the Garmin display.

How NMEA 0183 works

Here is how their NMEA 0183 interface works:

NMEA 0183 Cable Connections

NMEA 0183 is a standard communications format for marine electronic equipment. For example, an autopilot can connect to the NMEA interface of a GPS and receive positioning information. The GPS can exchange information with any device that transmits or receives NMEA 0183 data. See the following diagram for general wiring connections. Read your product’s owner’s manual for specific wiring information.

NMEA 0183 Wiring (Data cable)

The Garmin Oregon 450 uses the yellow wire to transmit, the white wire to receive and the Black and green wire for ground.

The M7 DB9 Serial Connector

The 9-pin serial I/O connector on the M7 is a female 9-p D-sub miniature connector having the following pins configuration.

Front-view of DB-9 connector on modem (female)

*Pin #*	*Name*	*Dir*	*Function*	*Level / Specification*
1	CD	out	Carrier detect
2	RxD	out	Receive data	Data out of the modem.
3	TxD	in	Transmit data	Data into the modem.
4	DTR	in	Data terminal ready	Normally ignored by the FireLine modem.
5	GND		Ground connection	Signal and power ground
6	DSR	out	Data Set Ready
7	RTS	in	Request to send
8	CTS	out	Clear to send
9	Power	In/out	DC power (not Ring signal)	User may supply the DC power to the modem on this pin.

Wiring the DB9

The Oregon’s “Data Cable” must be connected to the M7 transponder. This connection will allow the M7 to put icons on the screen of the Oregon display, showing the location of other tracked vehicles. The Raveon M7 GPS transponder uses a 9-pin “DB9? connector to connect to the Oregon. Solder the Oregon data cable wires onto a DB9 connector and plug the DB9 into the M7 transponder as shown below:

The white wire goes to pin two of the DB9, the yellow wire to pin 3, the black and green wires get twisted together and both go to pin 5, and the red wire goes to pin 9 of the DB9. It is recommended that you keep the fuse on the red wire when setting up the DB9 connector.

Configuring the M7 GX Transponder

Raveon has a designed the M7 GX transponder to work with Garmin Oregon Display or any other NMEA 0183 display that can accept the “$GPWPL” NMEA message. The $GPWPL is an industry standard message that the Garmin displays and many other GPS displays interpret as a way point command. The M7 GX outputs this $GPWPL message to put icons on the screen of the Garmin, and to move the icons around on its screen.

To configure the M7 transponder to output the $GPWPL message, set the M7 GX to GPS mode 2. To do this, put it into the configuration mode by send the +++ into the serial port. The M7 will respond with an OK. Type GPS 4 and press enter to put it into GPS 4 mode. GPS 4 is the mode that causes the M7 GX to output $GPWPL messages whenever it receives a status/position message over the air.

Raveon Technologies Corporation

990 Park Center Drive, C

Vista, CA 92081

sales@raveontech.com

760-727-8004

May 12, 2010May 12, 2010

Updating the RavTrack PC EXE file

It is usually possible to upgrade the RavTrack PC AVL software program to a newer version without re-installing the software as long as the major revision number is the same. (2.6 to 2.7, 3.1 to 3.3 …) Most upgrades can be performed by simply replacing the RavTrackPC.exe file which is stored in the program directory on your computer. This quick upgrade method avoids having to perform a full re-install of the RavTrack PC AVL software when simply upgrading to the current version.

To perform the quick update:

Close RavTrack PC. File > Exit
Click on the link below to download a copy of the latest .exe file:
http://ravtrack.com/downloads/RavTrackPCexe.zip or use the .exe file emailed to you from Raveon tech support.
Open the .zip archive folder by double-clicking on it.
Locate the directory on your computer that holds the RavTrack PC program. For most users the full path to this file is: C:/programfiles/raveon/RavTrack PC/
Rename the current RavTrack PC.exe file file to RavTrack PCold.exe.
Copy the new file from the named RavTrack PC.exe to your RavTrack PC program directory. For most users the full path to this file is: C:/programfiles/raveon/RavTrack PC/RavTrack PC.exe

You may now run RavTrack PC as you have been, and the new version will be executed. If there are data base upgrades to do, RavTrack PC will automatically perform the updates when it starts up.

May 10, 2010January 16, 2011

GPS Tracking with the Garmin 60C Series

The M7 GX series of GPS transponders may be directly connected to a Garmin 60C series of hand-held GPSs. All members of the Garmin 60C family have an RS232 option that is compatible with NMEA 0183 messages. This allows them to be used with Raveon’s RavTrack series of GPS radio transponders to make a complete GPS tracking system.

When connected to the M7 GPS radio transponder or the Atlas PLPersonal Locator, the Garmin’s map will show the location of all of the the user PLUS the location of all other transponders within radio range. This unique feature allows one to quickly, easily, and inexpensively, make a portable AVL system for tracking cars, trucks, racecars, construction equipment, or any thing Raveon’s M7 GX or Atlas PL transponder may be installed on.

The Garmin 60C series of hand-held GPSs have built-in interfaces for a “NMEA 0183” devices, which is another way of saying that they can connect to other devices using a serial cable. The NMEA 0183 is an RS232 serial connection that typically operates at 4800 baud. It is used to exchange way-point and other information between displays, GPS devices, and transponders.

When Raveon’s M7 GX transponder is connected to the Garmin display using the NMEA 0183 connection, the GPS radio transponder can put icons on the screen of the Garmin display. As the transponder receives updated positions from other vehicles, it updates the position of the tracked vehicle icons on the Garmin’s display.

Garmin 60C, 60CS, 60Cx Wiring

From the Garmin technical manual, here is how their NMEA 0183 interface works:

NMEA 0183 Cable Connections

NMEA 0183 is a standard communications format for marine electronic equipment. For example, an autopilot can connect to the NMEA interface on the Garmin 60C and receive positioning information. The Garmin 60C series can exchange information with any device that transmits or receives NMEA 0183 data. See the following diagram for general wiring connections. Read yourother product’s owner’s manual for more wiring information.

NMEA 0183 Wiring (Data cable)

Wiring the Serial Cable

The Garmin’s “Data Cable” must be connected to the M7 GPS transponder (or Atlas OL). This connection will allow the M7 to put icons on the screen of the Garmin display, showing the location of other tracked vehicles. The Raveon M7 GPS transponder uses a 9-pin “DB9” connector to connect to the Garmin. Solder the Garmin data cable wires onto a DB9 connector and plug the DB9 into the M7 transponder as shown below:

Connect the white wire(serial data from M7 into Garmin) from the Garmin’s Serial Cable goes to pin 2 of the M7’s RS232 DB9 connector. You do not need to connect the brown wire(serial data from Garmin), so you can trim it off. Connect the shield braid of the Garmin Serial Cable to pin 5 of the DB9. The red wire optionally can connect to pin 9 of the Raveon GPS transponder’s DB9 to power the Garmin from the DC source that powers the M7.

If you do not wire your own cable, but instead use Garmin’s RS232 serial cable, you will need to connect the Garmin’s RS232 cable to the M7 GPS transponder using a “NULL Modem” adaptor.

Configuring the Garmin

Set the NMEA communication of the Garmin to 4800 baud.

Configuring the M7 GX Transponder

Raveon has a designed the M7 GX transponder to work with Lowrance Display or any other NMEA 0183 display that can accept the “$GPWPL” NMEA message. The $GPWPL is an industry standard message that the Lowrance displays and many other GPS displays interpret as a waypoint command. The M7 GX outputs this $GPWPL message to put icons on the screen of the Lowarance, and to move the icons around on its screen.