Raven RPR 110 Manual

RPR 110
INSTALLATION
AND
SERVICE MANUAL

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Raven Industries
205 East 6th Street
Sioux Falls, SD. 57104
Voice: 1-800-243-5435
FAX: [phone]
www.ravenind.com

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TABLE OF CONTENTS
Introduction ....................................................................................................................................................................... 3
Functional Description ...................................................................................................................................................... 3
GPS Receiver ................................................................................................................................................................... 3
WAAS Receiver ................................................................................................................................................................ 4
GPS Antenna ................................................................................................................................................................... 4
Utility Software ................................................................................................................................................................. 4
Receiver Firmware updates ............................................................................................................................................. 4
Special Features .............................................................................................................................................................. 4
PPS Out .............................................................. 5
Radar Out ............................................................ 5
Advanced Message Forwarding .......................................... 5
Installation ...................................................................................................................................................................... 6
Initial Power up ..................................................... 6
Power ................................................................ 7
GPS Antenna .......................................................... 7
Antenna Cable ........................................................ 8
Operation ........................................................................................................................................................................ 9
Initial Startup ...................................................... 9
Normal Operation ..................................................... 9
Troubleshooting .............................................................................................................................................................. 10
Checking your installation ........................................... 10
Receiver Specifications .................................................................................................................................................. 11
Antenna .............................................................. 11
Configuration .................................................................................................................................................................. 12
Rear Panel Serial Interface .......................................... 12
Global Positioning System (GPS) ................................................................................................................................... 13
Differential GPS (DGPS) WAAS ..................................................................................................................................... 14
Raven Proprietary NMEA Messages .............................................................................................................................. 15
Sample GGA Message Structure ................................................................................................................................... 16
016-0159-862
4/01

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INTRODUCTION
The Raven RPR 110 GPS receiver provides highly accurate and reliable DGPS
navigation using WAAS satellite based DGPS corrections. This receiver is ideal
for GIS, precision farming or any other application where a high performance,
rugged, and simple to operate receiver is required.
FUNCTIONAL DESCRIPTION
The Raven RPR 110 is a 10 channel high-performance GPS receiver with a built-in
DGPS correction receiver. You can select the built-in WAAS receiver or use an
external RTCM source for your DGPS corrections. You can even let the receiver
automatically select its correction source by using the auto DGPS input mode
DGPS corrections are needed to improve the accuracy of standard GPS. If you
operate without DGPS corrections, the accuracy will be about 4 meters RMS. This
means the receiver would have an accuracy of about 12 feet in any direction 67% of
the time, or about 24 feet 95% of the time. Prior to the government turning off
Selective Availability (SA), this error was 100 meters RMS. With DGPS corrections,
the receiver can give you positions with a RMS accuracy of 1.4 meters, about 4
feet. If the receiver is operated with a DGPS correction source like USCG or
OmniStar service the accuracy would be about 3 feet (sub-meter) RMS.
Accuracy depends on many factors including the correction method and your range
from the source. With systems like OmniStar the range from reference station is
not as major a factor as it is for the USCG or WAAS systems. We are primarily
concerned with WAAS as the 110 is designed to use this as the primary source of DGPS
corrections. Considering that today there is a limited number of WAAS reference
stations, the accuracy will vary from about 1 meter to 1.4 meters RMS depending on
your location.
In addition to improved accuracy, DGPS corrections keep the calculated position
from jumping around when the receiver loses or picks up a new satellite. Without
DGPS these common occurrences will cause the position to suddenly jump to a new
point. Applications such as crop guidance will see accuracies of about 0.75 feet
RMS swath to swath when in WAAS DGPS. In this application the DGPS correction
source is critical, you don’t want the position to jump around while your spraying
a field.
For the functional description we can break the RPR 110 into several parts. Each
is described in the following sections.
GPS RECEIVER
The RPR 110 GPS receiver can generate real-time position solutions at a rate of 5
solutions per second. You can purchase an option that enables the 110 to output up
to 10 solutions per second. Position solutions are output via RS232 in NMEA
format messages.
The RPR 110 has two RS232 ports and can communicate at 1200, 2400, 4800, 9600,
19.2K, or 38.4K BPS on either/both port(s). The baud rate and the desired output
messages can be configured via the serial port using configuration messages.
NMEA format messages are standard for most GPS receivers and therefore should be
compatible with almost any software or hardware application designed to work with
GPS.

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The receiver comes from the factory with messages settings that should be compatible
with most applications. Refer to the connecting equipment manuals for information
about what message types and serial settings they require. By default, the 110
will output GGA and VTG messages on both ports. On port A these messages are output
at 19.2K BPS with 5 solutions per second. This is the optimum setting for
connection a guidance smart bar such as the Raven LB-5. Port B outputs the same
messages at 4800 BPS with 1 solution per second. This is optimum for applications
such as GIS or yield monitors.
WAAS RECEIVER
The 110 provides real time differential solutions using free corrections (WAAS)
broadcast from satellite. WAAS corrections are available without a subscription
free everywhere in the US, parts of Canada, Mexico and Europe using a compatible
system called EGNOS. These corrections are available 24 hours a day in all weather
conditions.
GPS ANTENNA
The GPS antenna is a low profile patch antenna, which receives both GPS and WAAS
signals. The antenna can be mounted to a metal surface using the internal magnetic
mount. The antenna is supplied with a 15-foot cable with a BNC connector.
UTILITY SOFTWARE
Utility software is not required to setup or use the receiver in most applications.
However, a utility program is available from Raven.
RECEIVER FIRMWARE UPDATES
Firmware is software, which resides inside the receiver. Raven continues to improve
the performance of its receiver products and sometimes makes special features
available. When this happens, a new version of firmware is created. You can request
this firmware from Raven. You will need to connect the receiver to a PC and run the
included programming software to update the unit. You should check with your dealer
for a new versions of firmware.
It should be noted that updates cover such things as bug fixes and performance
enhancements. Sometimes upgrades can also be programmed into the receiver using
the utility software. Up-grades also include things such as the 10 position
solutions per second option, which does have additional cost. The good thing is
that you can install these upgrades and updates. You will need to get a code from
your dealer or directly from Raven to install the upgrades but the process is
simple.
SPECIAL FEATURES
The RPR 110 has several special features that make it ideal for some applications.
Raven is always interested in adding special features to the receiver. If you have
a good idea, please send us an email at [email protected] or give us a call at
800-243-5435. We can’t guarantee that your idea will be implemented but we do want
to consider it.

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PPS OUT
The PPS output is normally used to provide a timing signal to another device. PPS
stands for Pulse Per Second and that’s what the signal does. Once each second the
signal pulses to indicate the start of a GPS second. The GPS second is a time
reference, which can be used to synchronize systems. If your application requires
very accurate time then the PPS output may be required.
The PPS output can also be used as a RADAR or Speed Log output as described in the
following sections.
RADAR OUT
The receivers can simulate a Doppler RADAR commonly used on agricultural equipment
for detecting speed. The GPS receiver is always calculating speed and can generate
the signals, which can be used by equipment requiring RADAR input. The receiver is
normally configured at the factory for RADAR output.
To use this feature you will need a special cable from Raven. It should be noted
that the GPS can only determine speed when it’s navigating. If a tree line blocks
too many satellites or if for some other reason the Receiver is unable to navigate,
then the RADAR output could become invalid.
The scaling factors and timing controls that govern the operation of this feature
can be controlled via a serial configuration message as defined in the Serial
Protocol Definition document. The receiver uses default settings that should
provide reasonable operation without the need for special configuration.
ADVANCED MESSAGE FORWARDING
The RPR 110 receiver supports advanced message forwarding in systems where the
application is designed to take full advantage of this feature. When enabled, all
messages received on Port B of the receiver will be time tagged with GPS time and
output on Port A in a special format.
The special format is basically just a prefix that includes the time tag. The time
tag is very important since it is referenced to GPS time and provided with
millisecond resolution. It can be used to completely eliminate latency issues.
Latency is usually only an issue in systems where GPS positions are used to locate
data coming from another sensor. If not accounted for, the latency of output can
show up as positional errors.
The advanced message forwarding takes care of latency problems in systems where the
other sensor can output NMEA style messages. This feature would also be useful in
systems with limited serial ports if the application developer were to take
advantage of this feature.

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INSTALLATION
Start by selecting a location for each of the various parts of the system. The
antenna, for example, should be carefully located per the guidelines given below.
Do not route the cables or permanently mount the antenna or receiver yet. Once the
system is operating, then you can route the cables and permanently mount the
receiver and antenna. This way, you won’t have as much trouble if a problem is
found in your initial locations.
INITIAL POWER UP
RPR receivers are reverse power protected so you should not hurt the receiver if
you follow these steps:
Make sure the receiver is not touching any metal surfaces. Place a piece of paper
or something between the receiver and the metal surface if necessary. If you have
the power backwards, a short will exist between the grounded metal surface and the
ground lead (which is power by accident). This short could burn up the ground wire
or blow a fuse. It’s a good idea to isolate the receiver from your chassis the
first time it’s powered up.
Connect the antenna to the receiver but don’t connect any of the other cables.
Right now you should have the antenna temporarily mounted and connected to the RPR.
You should be ready to apply power.
Turn off all the equipment on your machine. The receiver draws very little power
and this test will only take a few minutes. You want the other equipment off
because it might interfere with the receiver. Once you get the RPR working, you
will turn on the other equipment and watch for problems.
Apply power to the receiver. Watch the red LED power indicator. It should light up.
If it does not, you either don’t have power or power is connected backwards. If
you’re in a car, try turning the key on. Check the connections and try again. If
you still have trouble, refer to the Power section below. The yellow RTCM status
LED should blink then go out until a correction signal is located. If the RTCM
status light is flashing rapidly (4 times per second), the antenna cable is either
open or shorted.
Once you have the receiver power connected correctly go ahead and shut the power
off. Mount the receiver and repeat the previous step. If the power does not work
when you mount the receiver then you may have a positive ground system. If so, the
fuse in your machine is probably blown. You will need to isolate the receiver from
your chassis at all times in systems with positive grounds.
At this point, we have the power connected to the mounted receiver and the antenna
is connected. Watch the green LED GPS satellite-tracking indicator. The RPR 110
will be looking for satellites, which may take a few minutes. Eventually, if your
antenna has a clear view of the sky, the GPS light will flash once for each
satellite in view that it is using to calculate its position.

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Wait for the receiver to find and track the WAAS signal, it could take 15 or more
minutes before the receiver gets the necessary almanac data from the selected WAAS
satellite. This initial startup time is necessary only during the first time you
use the receiver. Once the broadcast is found the receiver will power up and start
receiving signals after about 5 seconds. If you don’t get a signal within about 30
minutes there could be some form of interference or you may not be in the coverage
area of the selected WAAS satellite. You should see the RTCM light come on and
remain steady if your getting corrections.
At this point, your receiver should be tracking satellites and generating good
differential positions. Start turning on the other equipment on your machine. As
each device is turned on, watch the LED status indicators for problems. A device
could interfere with the GPS satellites or WAAS signals. You should wait about 30
seconds after each device is turned on to see if the receiver stops tracking
satellites or if the RTCM indicator goes out. Finally, start up the machine and
again watch for any problems.
If after you turn something on, a problem is found, you can try moving the antenna
further away from that device. Check that the device is functioning properly and
also check its power connections. Some devices can generate too much noise
naturally or because of defective components.
Now you have the receiver working with everything that could interfere. Shut
everything off, mount the antenna, and route the cables. Once this is done, repeat
the power up steps.
The last few steps deal with connecting the other equipment that gets data from the
RPR 110. Refer to the manufacturer’s documentation for details such as baud rates
and required messages. It is very likely that you only need to connect the
interface cable to the device. The RPR 110 is configured, by default, to work with
most systems without any adjustments.
All configuration and WAAS data is stored in non-volatile memory inside the RPR
110. If you need to change the WAAS or GPS setups, you can run the receiver software
to make the changes.
POWER
The RPR 110 receiver needs DC power between 9 and 16 Volts. DC power is usually
provided by a battery on the machine or via a power adapter of some type. If your
unit came with an automotive power adapter, verify that your vehicle has a negative
ground system before you connect to power. If your unit came with an AC adapter,
you need only connect the adapter to an AC source.
GPS ANTENNA
GPS is a line-of-sight system, which means in order for the receiver to track the
satellites there must be an unobstructed path directly to them. Buildings, trees,
machinery, and human bodies are common obstructions. When locating the antenna,
find a place where the antenna will have an unobstructed view of the sky.

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Items such as electrical motors, generators, alternators, strobe lights, radio transmitters,
cellular phones, microwave dishes, radar, active antennas, etc., all generate electrical and
magnetic fields which can interfere with the GPS or WAAS signal. Mount the antenna away from
such potential sources of interference.
The GPS can be de-tuned by close proximity to other objects. For example, if you place the
antenna under fiberglass its performance could be degraded. Usually, if you lower the
antenna so that at least a quarter of an inch gap is made between the antenna and the covering
plastic or fiberglass, acceptable performance can be achieved. Metal or other dense materials
will completely block the GPS signals.
ANTENNA CABLE
The antenna cable should be routed around your machine so that it’s out of the way. Make sure
it is not subject to scraping or excessively sharp bending. Also, make sure the antenna cable
has some slack. It needs just enough to prevent strain on the connections.
It’s important that the cable’s outer insulation jacket is never broken. Make sure that the
cable is routed away from sharp or abrasive surfaces. Also, make sure the metal surfaces of
the connectors on the cable do not come in contact with the chassis of your machine.

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OPERATION
INITIAL STARTUP
Both the internal GPS and WAAS receiver must perform a Cold Start the first time
you power up the system. The GPS receiver will search the sky for satellites and
download data necessary for operation. The WAAS receiver will wait until the
required almanac data is received. The cold start will take up to 15 minutes but is
only required during the initial power up.
Always make sure the antenna is connected to the receiver before powering the unit.
Connect the serial cable provided between the RPR 110 and your computer, apply
power and verify that the red power LED is on. Allow the receiver to operate while
you install the software program on your computer. Turn off all unnecessary
electrical equipment to minimize electrical noise interference.
NORMAL OPERATION
Upon completion of the initial “Cold Start”, the receiver begins to operate in
“Normal Mode”. The unit should be operating in full DGPS mode within a few minutes
of power on.
All configuration and WAAS data is stored in nonvolatile memory inside the RPR 110
110. Configuration changes are made with utility software.
Be aware of possible satellite obstructions, which may interfere with GPS operation.
For high precision applications, watch your Horizontal Dilution of Precision
(HDOP) and WAAS Age of Data (AOD). The HDOP should be 2 or less and the AOD less
than 15 seconds.

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TROUBLESHOOTING
*Make certain the antenna is mounted so that it has a clear view of the sky and is
as far away from electrical noise sources as possible.
Attempt to isolate all problems as either:
· Receiver
· Antenna (including cables)
· Power
· Transmitting Site
· Serial Communications
a. Receiver
b. Peripheral device
CHECKING YOUR INSTALLATION
Monitor the effects on the beacon and GPS receiver performance as each device on
your vehicle is powered on. If the receiver stops operating properly when a device
is powered on, that device is causing interference and your antenna location may
need to change. For example, if running your engine causes interference, then
ignition noise or alternator noise is interfering with signal reception. Move the
antenna further away from the engine.
Receiver - Normally only 5 GPS satellites are required for good accuracy. View
the LED status indicator on the front panel and check the number of
satellites being tracked. Also look for the yellow RTCM light indicating
good differential reception.
Antenna - Check connections between the antenna and receiver. Verify the connectors
and cable are in good condition. An ohmmeter can be used to determine
if the antenna cable is open or shorted.
Power - Red power LED remains lit while power is applied.
Transmitting -If the receiver is operating in WAAS Mode, you may be out of range of
a satellite or the satellite may be off air. WAAS status information
is available on the Internet at www.FAA…
Serial Coms -Using GPS Mon software, check for proper communication settings baud
rate, and COM port number. Make sure the cable you use, if not
provided by Raven, is wired correctly. See section titled “Rear Panel
Serial Interface”.

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RECEIVER SPECIFICATIONS
Size 7.63” x 4.13” x 1.75” Protocols NMEA v2.2
Weight 20 ounces Position Accuracy 50 meter RMS, SA on
Operating Temperature -40°C to +70°C 4 meter RMS, SA off
Operating Humidity 5% to 95% R.H., 1.4 meter RMS, WAAS DGPS
Non-condensing, at +60°C Antenna Size 1.9”W x 0.6”H x 2.3”L
Channels 10 GPS, 1 WAAS Antenna Weight 65 grams
Update Rate 5/second Mounting Magnetic
(10/second optionally)
Power Consumption 4 Watts Typical Ant. Operating Temp. -40°C to +85°C
Voltage 9-16 VDC Ant. Operating Humid. 100% Condensing
ANTENNA
The ANT connector is used for interfacing between the RPR 110 and its Antenna/
Preamplifier assembly.
Pin Description
Center RF Input and +5VDC Output for Antenna Preamplifier
Shield Signal Ground

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CONFIGURATION
REAR PANEL SERIAL INTERFACE
The RPR 110 has two bi-directional RS232 serial interfaces available on a single
external DB9 female connector. Each port is assigned a single letter in uppercase,
‘A’ or ‘B’ and each one provides the necessary interfacing between the RPR 110 and
your navigation equipment.
DB9-F
Port A Signal Name
1 RAD/PPS
2 Port “A” TX
3 Port “A” RX
4 Port “B” RX
5 GND
6 Port “B” TX
7 No connect
8 +12 VDC Pwr Input
9 GND

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GLOBAL POSITIONING SYSTEM (GPS)
GPS is a satellite-based global navigation system created and operated by the
United States Department of Defense (DOD). Originally intended solely to enhance
military defense capabili-ties, GPS capabilities have expanded to provide highly
accurate position and timing information for many civilian applications.
An in-depth study of GPS is required to fully understand it, but not to see how it
works or appreciate what it can do for you. Simply stated, twenty-four satellites
in six orbital paths circle the earth twice each day at an inclination angle of
approximately 55 degrees to the equator. This constellation of satellites continuously
transmits coded positional and timing information at high frequencies in the 1500
Megahertz range. GPS receivers with antennas located in a position to clearly view
the satellites pick up these signals and use the coded information to calculate a
position in an earth coordinate system.
GPS is the navigation system of choice for today and many years to come. While GPS
is clearly the most accurate worldwide all-weather navigation system yet developed,
it still can exhibit significant errors. GPS receivers determine position by
calculating the time it takes for the radio signals transmitted from each satellite
to reach earth. It’s that old “Distance = Rate x Time” equation. Radio waves
travel at the speed of light (Rate). Time is determined using an ingenious code
matching technique within the GPS receiver. With time determined, and the fact
that the satellite’s position is reported in each coded navigation message, by
using a little trigonometry the receiver can determine its location on earth.
Position accuracy depends on the receiver’s ability to accurately calculate the
time it takes for each satellite signal to travel to earth. This is where the
problem lies. There are primarily five sources of errors, which can affect the
receiver’s calculation. These errors consist of:
1. Ionosphere and troposphere delays on the radio signal.
2. Signal multi-path.
3. Receiver clock biases.
4. Orbital satellite (ephemeris) position errors.
5. Intentional degradation of the satellite signal by the DOD (SA).
This intentional degradation of the signal is known as “Selective Availability”
(SA) and is intended to prevent adversaries from exploiting highly accurate GPS
signals and using them against the United States or its allies. SA accounts for
the majority of the error budget. The combination of these errors in conjunction
with poor satellite geometry can limit GPS accuracy to 100 meters 95% of the time
and up to 300 meters 5% of the time. Fortunately, many of these errors can be
reduced or eliminated through a technique known as “Differential.”

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DIFFERENTIAL GPS (DGPS) WAAS
DGPS works by placing a high-performance GPS receiver (reference station) at a
known location. Since the receiver knows its exact location, it can determine the
errors in the satellite signals. It does this by measuring the ranges to each
satellite using the signals received and comparing these measured ranges to the
actual ranges calculated from its known position. The difference between the
measured and calculated range is the total error. The error data for each tracked
satellite is formatted into a correction message and transmitted to GPS users. The
correction message format follows the standard established by the Radio Technical
Commission for Maritime Services, Special Committee 104 (RTCM-SC104). These
differential corrections are then applied to the GPS calculations, thus removing
most of the satellite signal error and improving accuracy. The level of accuracy
obtained is a function of the GPS receiver. WAAS is based on a network of approximately
25 ground reference stations that cover a very large service area. Signals from GPS
satellites are received by wide area ground reference stations and used to generate
DGPS corrections.
Differential GPS Broadcast Site

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NMEA MESSAGES
The RPR 110 receiver can be used to communicate with other electronic devices
including Raven’s RGL 500 Swath Guidance Light bar. A communication protocol (set
of rules) known as the NMEA 0183 standard has been established by the National
Marine Electronics Association. The NMEA 0183 standard contains numerous message
formats such as the ones described below which the RPR 110 receiver uses to
communicate with other devices.
RPR 110 NMEA Messages
ALM GPS Almanac Data
DTM Datum Reference
GGA Global Positioning System Fix Data
GLL Geographic Position
GRS GPS Range Residuals
GSA GPS Dillution of Precision (DOP) and Active Satellites
GST GPS Pseudorange Noise Statistics
GSV GPS Satellites in View
MSK MSK Receiver Interface
MSS MSK Signal Status
RMC Recommended Minimum specific GPS/Transit Data
VTG Course Over Ground and Ground Speed
ZDA Time and Date
PROPRIETARY NMEA MESSAGES
SLIB1S Beacon Receiver Channel 1 Status
SLIB2S Beacon Receiver Channel 2 Status
SLIDIF DGPS Status Information
SLIE1S External RTCM Channel 1 Status
SLIRTC RTCM Message Data Received
SLISDA Satellite Age of Data
SLISOL Position Solution
SLIWRN Receiver Warning Message

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SAMPLE GGA MESSAGE STRUCTURE
The following example of the GGA message shows the format typical of NMEA messages.

RAVEN INDUSTRIES
LIMITED WARRANTY
WHAT IS COVERED?
This warranty covers all defects in workmanship or materials
in your Raven Flow Control Product under normal use, maintenance,
and service.
HOW LONG IS THE COVERAGE PERIOD?
This warranty coverage runs for 12 months from the purchase
date of your Raven Flow Control Product. This warranty coverage
applies only to the original owner and is not transferrable.
HOW CAN YOU GET SERVICE?
Bring the defective part, and proof of date of purchase, to
your local dealer. If your dealer agrees with the warranty
claim, he will send the part, and proof of purchase to his
distributor or to Raven for final approval.
WHAT WILL RAVEN INDUSTRIES DO?
When our inspection proves the warranty claim, we will, at our
option, repair or replace the defective part and pay for
return freight.
WHAT DOES THIS WARRANTY NOT COVER?
Raven Industries will not assume any expense or liability for
repairs made outside our plant without written consent. We
are not responsible for damage to any associated equipment or
product and will not be liable for loss of profit or other
special damages. The obligation of this warranty is in lieu
of all other warranties, expressed or implied, and no person
is authorized to assume for us any liability. Damages caused
by normal wear and tear, mis-use, abuse, neglect, accident, or
improper installation and maintenance are not covered by this
warranty.

Manual Rev. A, RPR110,
04/01 #016-0159-862