Raveon’s RavTrack GPS tracking system is the ideal golf cart tracking system to track golf-carts and golf course maintenance vehicles. Golf Cart Tracking

RavTrack GPS tracking delivers helpful, real-time location information and displays it on a map image of your golf course. You can track the carts, mowers, trucks, and workers.  You can see where you mowed each hour, day, or week. You can quickly locate carts to deliver food and beverages.

It also can detect potential theft or abuse of your carts and equipment.  You can configure keep-out zones and many other rules to notify the ranger or security if a rule is violated.

Because Raveon’s RavTrack system uses VHF and UHG licensed UHF radio frequencies, you can easily cover your whole course and have no monthly air-time fees.  The RavTrack system is also available on the VHF MURS radio band, which is license-free.  It works where GSM radio-based systems don’t and because the airtime is free, your update-rate of cart position and status is the fastest in the industry.  You can easily track 75 carts with 15-second update rates.

And unlike the short-range 900Mhz and 2.4gHz solutions, RavTrack will cover your course, and reliablye show you where your vehciles are.

RavTrack GPS tracking improves golf course operations by:

A comparison of GPS tracking and AVL systems.  RavTrack versus cellular GSM or GPRS.

Most GPS vehicle tracking systems use a “cellular” wireless telephone carrier system to collect position information from the fleet in the field and transport that information back to headquarters.  You may see acronyms such as GSM or GPRS describing the system.  The RavTrack system uses a very different approach, that of local user based radio.  These two approaches will often appeal to different types of users.  However, one thing is clear; if RavTrack can meet your needs it is by far the superior choice over cellular.  Here are some of the most common reasons why.

Total cost of ownership

Every cellular system has recurring service fees, typically on a per vehicle per month basis.  The RavTrack system has no monthly fees.  Consider how long they will want to have a tracking system.  Likely you will want it “forever” and you should recognize that once you have RavTrack installed you have no more expenses.  In some cases it may cost more to initially purchase and install RavTrack versus a cellular system but over several years time it can cost much less, even if the monthly fees the operators charge are not very high. 

Also, RavTrack protects your tracking system from budget cuts.  If you determine RavTrack and the celluar systems both cost the same over 3 years, RavTrack is the only of the two systems you know you can keep.  If you are forced to cut your budget next year or later, then your cellular system, and any investment you have made is at risk.  RavTrack is not at risk.

Performance

RavTrack will provide very frequent and very fast updates.  Both are important.  With RavTrack you can hear back from the fleet at very frequent intervals.  How does this compare to the cellular system?  Perhaps you feel frequent updates are unimportant, but if later things change can the cellular system even provide these faster updates?  If so, does the monthly charge increase?

RavTrack updates are not only frequent but fast as well.  When a vehicle sends the current position with RavTrack you can receive this position right away (often less than one second later).  Many cellujlar systems will take 15 seconds, 30 seconds, or even several minutes before the operator receives the position report from the vehicle

Both of these factors are important to operations that serve in emergencies such as police, fire, and ambulance.

Capability

With RavTrack you can track fleet fleet or personnel from other vehicles or mobile posts?  Any RavTrack vehicle can receive from the other vehicles or personnel automatically, and with a proper display can see the other members on a map in real time.  Even personnel on foot can be provided a hand-held display.  Almost no other system has this capability.  This is an important benefit to supervisors in the field or any time teams need to work together.  You can have this capability now, or add it later.  You do not lose this capability, nor general tracking capabilities if part or all of your fleet travels into an area where cellular service is not available.

Reliability

The celllular service is a shared service used both for voice and data.  Any high demand or peak use of the cellular system, either at a single receiver or on the system overall, such as can be caused by a disaster or just a popular event, can overwhelm the cellular system and may cause the system to be too overloaded to be useful for tracking.  Often, this occurs when you need your tracking capabilities most.  The RavTrack system is dedicated to your fleet and not subject to peak use concerns.

Security

RavTrack messages can be encrypted with 128 bit AES, making them indecipherable to outside parties.  Furthermore, RavTrack data is stored only on the customer devices and not available to unauthorized users, including those that might be in a 3^rd party data center.

Powerful Software

RavTrack PC software is extremely rich with features, unmatched by most other software packages.  RavTrack provides extensive geofences, rules, and alarm capabilities.  RavTrack PC enables sophisticated user security measures to ensure only the right people have access to important information, and features in depth historical logging, playback, and reporting capabilities.  For a detailed list of RavTrack PC features and functions refer to http://ravtrack.com/RavTrack-PC-Functions.html

Flexibility

As the customer you are always in control of the RavTrack system and can make adds, deletes, and changes whenever you need.  You do not have to submit a request to a vendor and wait for the vendor to perform (or mis-perform) on either routine on uncommon requests.  Furthermore, as a RavTrack software implementation is specific to each customer and not shared, we are capable of providing you something unique or special to meet your individual needs, and do not need to be concerned about a specific change affecting other parties.

Adaptability

With RavTrack you are not limited to the map your vendor provides.  Almost any map can be converted into a RavTrack map, including aerial photographs!  Choose the map or view that best meets your needs, when you need it.  If your environment changes RavTrack allows you to bring in the latest map with the latest data, providing uncompromised adaptability.

Options

The RavTrack system is supported by more than 10 other software packages from parties other than Raveon, giving you far more choices than any other system on the market.  Most cellular systems provide only one software option.

The RavTrack system includes devices for both vehicles as well as personnel.  Many other systems only provide equipment to track vehicles.

How can I convert this high precision map that I used with my previous tracking software, the map info is stored in .dat format?

We can easily convert over data files that have stored map information. We will use Global Mapper 12 to load the files into our editable area, set our projection, and then export as a usable Geotiff. We will then convert that Geotiff into .Maplib Format.

The following steps outline the procedure:

1. Start Global Mapper 12 and select (Open all files in a Data Tree).

For our example, we have have a set of data files stored in a local directory. Select (open all files in a directory tree) and choose the directory your files are stored in.

2. Set Options for your .Dat File

The ASCII options window will show for each data file that loads. For our example, we will leave the default values and select OK. Repeat this for each Data File that loads. Note, depending on the data file and stored vector data, not all data may successfully transfer over. You may see a window that asks "Cancel all remaining data file loads", select no and continue loading your files.

3. Map is Now Loaded Into Global Mapper.

The data files have successfully loaded. We can now edit and export the map image.

4.Set Projection

We must now set the correct projection. Select (Configure) under the Tools menu. Then Select the (Projection Tab). Set the projection and zone your map covers. For our example we are using UTM, ZONE 50. There are many reference maps that can be found online with outlined UTM zones. It is very important that you select the correct projection and zone in order the the exported map image to be usable with RavTrack PC. Select OK when finished.

5. Export Geotiff

Select (Export elevation grid format) under the file menu. In the following windows select Geotiff as your export format. We will now export the map file.

6. Select Output Options

The export options window will allow us to adjust the output settings. Our focus is on the sample spacing/scale option, and the world file option highlighted in the above screen shot. The scaling option will allow you to adjust the output resolution of your image. Increase the values for smaller resolution maps, and decrease these values for larger resolution maps. Select the generate world file option and click OK. Save to a known directory that you can easily find again.

7.

Open RavTrack PC. Click (Map Creation Tool) under the tools menu. We will now take our Geotiff and convert it to .MapLib. Select (New Map).

8. Select your .tif Image

Find the directory in which you saved your Geotiff. Select and open you .tif image.

9. New Map Settings

Leave the new map settings defaulted and select OK.

10. Set Projection Settings

Set the Country, Grid, and Zone that the map covers. Note, these parameters must match the settings you placed when creating the Geotiff. Select Next when complete.

11.Save Your MapLib

Your Geotiff has now been converted. Select (Save Maplib as) under the file menu. Save your completed map into your RavTrack PC map directory. This directory location can be found by selecting Help>About RavTrack under RavTrack PCs help menu. After the Save is complete, exit the map creation software.

12. Select Your New Map

Your Map is now ready to be used with RavTrack PC. Select (Program Properties) under the file menu in RavTrack PC. Your map should be located in the lower left hand area of the window. Select your Map and click Save and Exit.

13.Success!

The conversion is complete. Select (Go to Map) under the view menu. Center your map, and your done.

INTRODUCTION:

WASS (Wide Area Augmentation System) is the next generation standard for implementing higher accuracy GPS systems. As demand for GPS continues to grow, the US government has implemented a more robust system to meet the needs of next generation tracking and improved reliability while still maintaining standard equipment in the field. Raveon Technologies has taken advantage of this new standard by adding WAAS to both their M7 GPS transponders and their industry leading RavTrack precision tracking solution.  

BRIEF HISTORY OF LORANC/GPS/DGPS/WAAS:

In an effort to support military and commercial aircraft, LoranC was the first implementation of modern GPS technology. Employing multiple ground based radar towers (sometimes compared to as bowling pins) typically near airports and larger cities, LoranC provided excellent positioning for its time as a method to keep track and position aircraft. The downside of LoranC was that it was less available in rural areas and completely unavailable over large bodies of water. LoranC was also not accurate enough to support extremely bad weather and non visual approaches.

GPS technology was next on the scene providing a 10x and greater improvement of positioning while solving the aforementioned approach problems. Using satellites and a low cost receiver approach, GPS took tracking from an expensive professional solution to a system that is now available in most cars, watercraft, and personal equipment.

Adding a differential mathematical approach, a specialized receiver, and land based FM towers, DGPS further improved positioning by another 10x. The downside of the approach is that it relies on line-of-site (to the towers) and provides spotty coverage in smaller towns and rural areas that don’t have the luxury of piggybacking on towers of local FM radio stations. Also of note is that a DGPS receiver is not compatible with a off the shelf consumer GPS unit.

WAAS is the latest approach and by far the most accurate. Using a combination of GPS satellites, ground stations, and geo-stationary satellites (see below for greater detail), accuracies up to less than 1M can be attained using standard off the shelf GPS equipment. With this type of spec, WAAS allows for new markets and solutions requiring a higher level of accuracy previously unattainable with existing solutions.

Some of these markets that Raveon Technologies WAAS enabled GPS transponders now support include vehicle collision avoidance, precision vehicle tracking and navigation, tighter and more specific geo-fencing, more accurate personal tracking, precision agriculture plotting, along with several other position dependent solutions.

TOPOGRAPHYOF A WAAS SYSTEM AND HOW IT WORKS:

WAAS is a combination of ground base stations and satellite transceivers used to greatly improve the accuracy and performance of conventional GPS. Conventional GPS relies on using satellite transceivers “only” which are subject to ionosphere disturbances (billows), satellite orbit errors, timing, and clocking errors. By augmenting ground based stations, the errors associated with GPS are greatly minimized if not eliminated while also adding monitoring and real time adjustment of the GPS satellites themselves.

The system installed in North America is as follows: 35 plus ground base stations called Wide area Reference Stations (WRS) along with the existing satellites provide correlation data that is sent to 2 Wide area Master stations (WMS) on each coast to create a corrected signal. This corrected signal is then retransmitted by a geo-stationary satellite called a Ground Uplink Station  (GUS) that is fixed at the equator.

The system provides for guaranteed accuracy of  3 meters or less with typical accuracies approaching sub 1 meter (multiple samples may be accumulated to achieve even better specs). Adding to the accuracy improvement, uptime approaches 99.999% with a downtime of 5 minutes per year while conventional GPS can only guarantee 4 days per year of downtime.     

SPECIFICATIONS OF WAAS VERSES STANDARD GSP, DGPS, AND LORANC:

The following is a table of specifications and observed lab measurements of the various positional methods used in the US. 

As can be seen from the table, Raveon Technologies WAAS enabled transponders provide the most accurate tracking and positioning available while employing standard GPS gear. DGPS comes in at second, but as discussed, is only employed and is dependable in cities and urban areas where FM towers are available and line of site can be attained using the specialized DGPS gear. Standard GPS will continue its success in supporting the large consumer but lower precision auto, marine, and personal tracker market. LoranC, although the least precise, has a large installed base in the personal and small aircraft segment. 

Below is a comparison of the position error of a GPS tracking system using WAAS augmentation and DGPS.  In this test, the horizontal accuracy was very good with each method. The WAAS system had much better verticle accuracy. 

CONCLUSION:

By implementing a WAAS GPS M7 or RavTrack system from Raveon Technologies, precision accuracy approaching sub 1 meter is attainable and repeatable using existing GPS receiver systems allowing for new applications and end-products in the positioning and tracking space.

The purpose of this tech blog entry is to guide a RavTrack PC user in acquiring a usable Geotiff Map File from Global Mapper 12. This Geotiff can be converted to .Maplib format and displayed on RavTrack PC.  Please note that earlier versions of Global Mapper, including version 10.02 and 11.00, can be utilized for the same operation, however, some specific  WMS data sources are not built in.

Global Mapper 12 is a powerful mapping software that allows access to high resolution geospatial imagery which can be downloaded, edited, and extracted. We are going to focus on the downloading and extracting aspect of the software.  Most RavTrack users have applications that require the use of street, satellite (Aerial), topographic, and similar maps. Obtaining these maps can become somewhat difficult; however, with software packages such as Global Mapper, you can easily obtain a usable Geotiff that can be displayed on RavTrack PC.

To accomplish this please follow these steps:

1. Start up Global Mapper 12.

Ensure you have the registered version. The trial version may limit your ability to extract the geotiff map image.

2. Select (Download free maps/imagery)

Select the type of map you wish to use. Common maps include openstreetmap.org and NAIP Color Imagery. Enter the area location details in the (Select download area) section. The amount of area selected is proportional to download time, larger areas will take longer to process and download.

3. Configure Projection

After your map image has loaded on the screen, select (Configure) under the tools menu.

4. Set the Projection Parameters.

Select (UTM) and the (Zone) for your map’s area. There are many reference maps online which outline the UTM Zones. For our example we are using UTM projection in Zone 11. After you have selected UTM and your Zone, click (OK). Your map is now in the correct projection.

5. Select (Export Raster/Image Format) in the file menu.

Your Map is now ready to export. Ensure you have selected the area you wish to cover.

6. Select Geotiff as your export format.

7. Set Export Options

This is where you can adjust the map image you are exporting. For our example we are going to focus on the (Sample Spacing/Scale) and (World File) option. The scaling option allows you to control you resolution. If you wish to have a high resolution map (More Detail and lower elevation) decrease these values, for lower resolution and a smaller map file, increase these values. Ensure you select (Create TFW (World File)). Once this is done, click OK.

8. Start RavTrack PC and select Map Creation Tool

After the Geotiff export is complete, open RavTrack PC. Select (Map Creation Tool) in the tools menu. We will now begin to convert the Geotiff to a usable RavTrack Image (.MapLib format).

9. Select New Map

This is the map creation software that will convert the geotiff to .maplib.

10. Select the Geotiff Image

Find the directory of the Geotiff image and select the .tif image that exported by Global Mapper. Once selected click OK and the geotiff will be loaded into the map creation tool.

11. Select OK to the Default Settings.

Click OK to the default settings here and select OK.

12. Click Yes to World File

The map creation tool will ask you wif you would like to use the world file you selected in Global Mapper. Click Yes.

13. Select Grid

This section is vital, incorrect values will cause the map image to display incorrect coordinates. Enter your (Region), (Grid), and (Zone). For our example we are located in the United States, using UTM North, and in Zone 11. Once complete, click next.

14.Verify Coordinates

You have completed the conversion process. Click anywhere on the map and the coordinates of that location will display on the lower left hand side. You can verify these coordinates by referencing them with known locations from an alternate source such as Google Earth.

15. Save your Map

Select save MapLib as under the file menu.

16. Locate your RavTrack Map Directory.

Locate your RavTrack PC map directory. You can find the specific location of this folder by selecting ABOUT RAVTRACK under the RavTrack PC help menu. Save your .MapLib.

17. Open Program Properties

Open Program Properties located under the file menu in RavTrack PC. Your Map will be located on the lower right hand side. Select your Map file and click save and exit.

18. Success!

You have successfully converted a Geotiff to .Maplib. If your map does not show on the screen immediately, select VIEW>GO TO MAP. Your map will display and you can now use it with RavTrack PC.

So, you set up RavTrack PC and connected your base station to the computer running RavTrack PC.  And yet, nothing is happening. This article describes some common solutions to communication problems in a RavTrack GPS tracking system.

Connection/COM port issues

When the system is running, select View > Communication Statistics from the main screen.  This will show you how the various RavTrack PC communication channels are operating.  In the second column of the communication statistics is a message counter with two numbers AAA/BBB.  AAA is the number of NMEA messages from the local radio connected to RavTrack PC.  BBB is the number of PRAVE messages that came into RavTrack PC through this channel.  A PRAVE message occurs whenever the “base” radio receiver connected to RavTrack receives a GPS position report over-the-air.

If the message counter shows 0/0, then there is no communication with the base radio.  This is probably due to on of the following things, and will have to be remedied:

1. The Base radio is off.
2. The base radio is not connected to the PC running RavTrack PC.
3. The COM port that the base radio is plugged into is not configured correctly (Program Properties > Congure I/O to repair it).
4. The cable connecting the base to the PC is bad, or is a “Null modem”. For most computers, the connection will be a USB or a 9-pin serial cable wired 1:1.
5. The COM port that the base is connected to is in use by another software program.

No Over-the-Air Reception

If the message counter in the Communication Statistics window shows  NNN/0 where NNN is some non-zero number, and the second number is 0, this means the base radio is communicating with RavTrack PC sending NMEA messages, but nothing is being received over the air.   The COM port and cables are fine, but there is a problem receiving the over-the-air messages.  The most common problems that will cause this and need to be corrected are:

1. No antenna is connected to the base radio.
2. The base antenna cable or connector is broken.
3. The KEYPHRASE is not set.  The KEYPHRASE encryption code must be the same in all radios.  The factory default KEYPHRASE is “RAVEON”.
4. The base receiver is not set to the correct frequency. Note: the base’s STAT LED will blink green each time it receives a message from a GPS transponder.
5. The TOID (ATDT) in the mobile transponders are not set to the base station’s ID.  Note: you can set the base station address mask to ATMK 0000 to receive all messages regardless of TOID.
6. The mobile transponders are not transmitting.  Reasons for them not transmitting may be:
   A. No power to the transponder.
   B. No GPS satellite lock.  The transponder’s GPS antenna must be able to see the sky.
   C. The transmit frequency is incorrect.
   D. The KEYPHRASE is wrong.
   E. Their antenna or coax cable is broken or disconnected.

Common Configuration Errors

From the factory, all Raveon GPS transponders and base stations are configured to work out of the box.  You will not need to set anything just to verify they work.  But, you may bave to modify some settings for your particular installation before you put them in the field. The following parameters within the base station and GPS transponders must all be set correctly and to the same settings on all units for your system to work:

1. KEYPHRASE
2. Over-the-air baud radio. Do not change without consulting the factory.
3. TOID of the transponder must be the ID of the base.
4. Group number (ATGP).  The factory  default is none, and is typically left at none (ATGP 0).
5. TDMATIME and SLOTTIME parameters.

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.

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

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)

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

With any complex communication system, there can be problems which cause it to not work as planned.  It could be a power failure,  electrical failure of a component, computer crash, cut cable, broken antenna, lightning damage, or a host of other unforseen issues.  Most of these are easy to deal with, but quickly being notified when they happen can be important.

You are able to monitor your GPS tracking system if your system uses RavTrack PC or any other GPS tracking software that allows you to create an alert if a vehicle does not report in.  By configuring your RF infrastructure components to also work as GPS transponders, the same tools used to monitor vehicles can be use to monitor your system.

For example, if you use a repeater in your system, configure it to periodially tranmsmit its GPS position also.  This way, if the antenna fails, power goes out, or it just stops working, your GPS monitoring software will send an alert.

With RavTrack PC, you can setup an Alarm and Monitoring Rule to help you monitor your radio network, server, or system operation.  Using the “No Reports” parameter monitoring feature, you can configure an alert to send an email to IP or Management personnel if your system stops working.

Monitoring System Components

To determine if part of all of the GPS tracking system is working, the periodic GPS position messages sent over the air may be monitored, and if they stop coming in, an alert can be generated to notify personnel of a potential system problem.

The easiest way to monitor the radios in your network is to configure them to report their GPS positions over-the-air.  Then configure an Alarm and Monitoring Rule using the No Reports parameter monitor to send an email if the item being monitored does not report in within a preset time period.  This will cause the Alert email to be sent if a part of the GPS tracking system fails such as broken antenna, cut cable, failed power supply, lightning damage, and unplugged serial cable.

Most radio transceivers, such as the M7 GX series of radios, which are used at a base station site may also be configured to output standard NMEA GPS position messages every 5 seconds.  This periodic local NMEA GPS message can also be used to determine if the base station radio is alive and operational.  To use the NMEA GPS position in an alert, you must configure the Communication Channel to interpret the NMEA GPS data as a tracked object in your system.  There is an option to Interpret GPS data w/o ID as ObjectData in the Systems Communications configuration tab.  If this enabled, RavTrack PC will create a new tracked vehicle with an ID 900X where X is the communications channel.  RavTrack PC will place the location of the vehicle 900X at its GPS position.

If there is a GPS transponder in the network that always is powered on and working, then the position report from that unit may also be used to check for system operation.

Monitoring a Server running RavTrack PC

The technique described above will work to monitor individual system components such as receivers, cabling, repeaters, and antennas.  But if a main server running RavTrack PC fails, the failed server cannot report itself failing.  A solution to this dilemma is to also run RavTrack PC on a management workstation, and then configure the same No Reports Alert on the workstation.  If the a server fails, causing the RavTrack system to stop recording GPS tracking data, the workstation’s No Reports Alert will then trigger, send an email, and/or alert the operator.