Campbell GPS16X-HVS User manual

GPS16X-HVS
GPS Receiver
Revision
: 05/2020
Copyright ©
2003 – 2020
Campbell Scientif
ic, Inc.

i
Table of Contents
PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.
1. Overview .................................................................... 1
1.1 Default Settings....................................................................................1
1.2 Compatible Data Loggers.....................................................................2
1.3 Common Accessories...........................................................................2
2. Precautions................................................................ 2
3. Initial Inspection ........................................................ 3
4. QuickStart .................................................................. 3
5. Specifications ............................................................ 5
6. Installation ................................................................. 6
6.1 Wiring ..................................................................................................6
6.1.1 Using with an A300 ......................................................................8
6.2 Mounting..............................................................................................9
7. GPS Data .................................................................... 9
7.1 $GPGGA Sentence (Position and Time)............................................10
7.2 $GPRMC Sentence (Position and Time)............................................11
8. CRBasic Programming............................................ 11
8.1 GPS() Instruction ...............................................................................11
8.2 Example Program Using GPS() Instruction .......................................13
9. Troubleshooting ...................................................... 14
9.1 Testing and Evaluating Serial Communications ................................15
9.1.1 Through a Direct Connection to the GPS16X-HVS ...................15
9.1.2 Through a Data Logger Connected to the GPS16X-HVS...........15
9.2 NMEAStrings Variable Populated, but Clock Not Setting ................16
Appendices
A. Changing GPS16X-HVS Settings.......................... A-1
A.1 Computer Connections.................................................................... A-1
A.1.1 Using the A200 ........................................................................ A-1
A.1.1.1 Driver Installation.......................................................... A-1
A.1.1.2 Wiring............................................................................ A-2
A.1.1.3 Powering the Sensor...................................................... A-3

Table of Contents
ii
A.1.1.4 Determining which COM Port the A200 has been
Assigned .................................................................... A-3
A.1.2 Using the DB9-Female-to-Terminal-Block Interface .............. A-3
B. Serial Programming............................................... B-1
Figures
1-1. The GPS16X-HVS terminates in pigtails for direct connection to
our data loggers.................................................................................1
6-1. CR1000 to GPS16X-HVS connection .................................................7
6-2. GPS16X-HVS mounted using a CM235 Magnetic Mounting Stand ...9
A-1. A200 Sensor-to-PC Interface .......................................................... A-2
Tables
1-1. Default Settings....................................................................................1
6-1. Data Logger Wiring .............................................................................7
6-2. CR9000X Wiring .................................................................................8
6-3. GPS16X-HVS Wiring to A300 Terminals and Data Logger
Terminals ..........................................................................................8
6-4. A300 Cable Wiring to Data Logger Terminals....................................9
7-1. NMEA $GPGGA String Definition ...................................................10
A-1. A200 Wiring.................................................................................... A-2
A-2. DB9-Female-to-Terminal-Block Interface Wiring.......................... A-3
CRBasic Examples
8-1. Reading the GPS Using the GPS() Instruction...................................14
B-1. Reading the GPS Using Serial Programming...................................B-1

1
GPS16X-HVS GPS Receiver
1. Overview
FIGURE 1-1. The GPS16X-HVS terminates in pigtails for direct
connection to our data loggers
The GPS16X-HVS is a complete GPS receiver manufactured by Garmin
International, Inc. Campbell Scientific configures the GPS16X-HVS to work
with our data loggers and modifies its cable so that the cable terminates in
pigtails. The pigtails connect directly to the control terminals of our data
loggers or with the aid of an A300.
The GPS16X-HVS includes the GPS receiver and antenna in the same housing
with one cable for the power supply and communications. The GPS antenna
must have a clear view of the sky. Generally, the GPS antenna will not work
indoors.
The GPS16X-HVS is a 12-channel GPS receiver that supports FAA Wide Area
Augmentation System (WAAS) or RTCM differential GPS. Also supported is
the 1 Pulse Per Second (PPS) timing signal. The cable connections provided
with the GPS16X-HVS do not support differential GPS correction. The cable
can be modified by the user if differential correction is required.
1.1 Default Settings
TABLE 1-1 shows the default settings of the GPSX16-HVS.
TABLE 1-1. Default Settings
Baud Rate 38400 bps
Parity N (no parity)
Stop Bit 1
Sentences Output GPGGA, GPRMC
PPS 100 ms

GPS16X-HVS GPS Receiver
2
1.2 Compatible Data Loggers
Compatible Contemporary Data Loggers
CR300
Series
CR800
Series CR6 Series CR1000X CR1000 CR3000 CR9000X
* * * **
*If PPS is required, the A300 Power and Signal Converter is needed.
**CPU Card RS-232 port only.
This manual provides information only for CRBasic data loggers.
For retired Edlog data logger support, see an older manual at
www.campbellsci.com/old-manuals.
Except for the CR9000(X), our data loggers use the CRBasic GPS() instruction
to read the GPS16X-HVS. To use the PPS functionality, some data loggers
need an updated clock chip. The clock chip is factory replaced (refer to
Assistance page for more information). Data loggers with the following serial
numbers need an updated chip:
Data Logger Serial Number
CR1000M < 20409
CR800 Series < 7920
CR3000 < 3168
In August 2014, Garmin changed the PPS output signal from 5 V to 3 V. Units
with serial numbers greater than 1A4189318 have a 3 V PPS output signal.
Because of this, the CR800-series, CR1000, and CR3000 data loggers need the
A300 power and signal converter to use the PPS signal output. The A300 is
NOT required for the CR6-series, CR1000X, or CR300-series data loggers.
1.3 Common Accessories
The following common accessories are described at
www.campbellsci.com/gps16x-hvs:
•GPS16X-HVS Magnetic Mount
•CM235 Magnetic Mounting Stand
•A200 Sensor to PC Interface
•A300 Power and Signal Converter
•DB9 Female to Terminal Block with Hood and Hardware Kit
2. Precautions
•READ AND UNDERSTAND the Safety section at the front of this
manual.
•When wiring the GPS16X-HVS, connect Ground before connecting 12V.
NOTE

GPS16X-HVS GPS Receiver
3
3. Initial Inspection
Upon receipt of the GPS16X-HVS, inspect the packaging and contents for
damage. File damage claims with the shipping company.
4. QuickStart
A video that describes data logger programming using Short Cut is available at:
www.campbellsci.com/videos/cr1000x-datalogger-getting-started-program-
part-3. Short Cut is an easy way to program your data logger to measure the
GPS16X-HVS and assign data logger wiring terminals. Short Cut is available
as a download on www.campbellsci.com. It is included in installations of
LoggerNet, RTDAQ, PC400, or PC200W.
The following procedure also describes using Short Cut to measure the
GPS16X-HVS.
1. Open Short Cut and select to create a new program.
2. Double-click the data logger model.
3. In the Available Sensors and Devices type GPS16X-HVS or find the
sensor in the Sensors > Miscellaneous Sensors folder. Double-click
GPS16X-HVS. Specify the Local time offset, whether to synchronize
datalogger clock to GPS clock, and the Maximum time difference
allowed between datalogger clock and GPS clock. You may also change
any of the default labels for the returned GPS values.

GPS16X-HVS GPS Receiver
4
4. Click on the Wiring tab to see how the sensor is to be wired to the data
logger. Click OK after wiring the sensor.
5. Repeat steps three and four for other sensors. Click Next.
6. In Output Setup, type the scan rate, meaningful table names, and Data
Output Storage Interval.

GPS16X-HVS GPS Receiver
5
7. Select the output options.
8. Click Finish and save the program. Send the program to the data logger if
the data logger is connected to the computer.
9. If the sensor is connected to the data logger, check the output of the sensor
in the data display in LoggerNet, RTDAQ, PC400, or PC200W to make
sure it is making reasonable measurements.
5. Specifications
Physical
Size: 86 mm (3.39 in) diameter, 42 mm (1.65 in) high
Weight: 181 g (6.4 oz) without cable, 332 g (11.7 oz) with 5 m
cable
Cable: PVC-jacketed, 5 m, foil-shielded, 8-conductor, 28 AWG
Electrical Characteristics
Input Voltage: 8.0 VDC to 40 VDC unregulated
Current Drain: 65 mA @ 12 VDC
GPS Receiver
Sensitivity: –185 dbW minimum
GPS Performance
Receiver: WAAS enabled; 12 parallel channel GPS receiver
continuously tracks and uses up to 12 satellites, 11 if
PPS is active

GPS16X-HVS GPS Receiver
6
Acquisition Times (Approximate)
Reacquisition: Less than 2 s
Hot:1 s (all data known)
Warm: ~38 s (initial position, time and almanac known,
ephemeris unknown)
Cold: ~45 s
SkySearch: 5 min (no data known)
Sentence Rate: 1 s default; NMEA 0183 output interval configurable
from 1 to 900 s in one second increments
Accuracy: GPS Standard Positioning Service (SPS)
Position: Less than 15 m, 95% typical (100 m with selective
availability on)
Velocity: 0.1 knot RMS steady state
DGPS (USCG/RTCM)
Position: 3-5 m, 95% typical
Velocity: 0.1 knot RMS steady state
DGPS (WAAS)
Position: Less than 3 m
Velocity: 0.1 knot RMS steady state
PPS Time: ±1 microsecond at rising edge of PPS pulse (subject to
selective availability)
Dynamics: 999 knots velocity (limited above 60,000 ft, 6g
dynamics)
Interfaces: True RS-232 output, asynchronous serial input
compatible with RS-232 or TTL voltage levels, RS-232
polarity. Selectable baud rates (4800, 9600, 19200,
38400)
PPS: 1 Hz pulse, programmable width, 1 microsecond
accuracy
Power Control
Off: Open circuit
On: Ground or pull to low logic level < 0.3 VDC
Environmental Characteristics
Temperature: –30 to 80 °C operational, –40 to 80 °C storage
6. Installation
6.1 Wiring
The GPS16X-HVS connects directly to a CR6-series, CR3000, CR1000X,
CR800-series, CR300-series, or CR1000 data logger (see TABLE 6-1).
However, if PPS is required, the A300 Power and Signal Converter may be
required for use with the CR800 series, CR1000, and CR3000. See Section

GPS16X-HVS GPS Receiver
7
6.1.1, Using with an A300 (p. 8). The CR6 series, CR1000X series, and CR300
series do not require the A300.
Use the DB9-Male-to-Terminal-Block interface to connect the GPS16X-HVS
to the RS-232 port of the CR9000X CPU card. See TABLE 6-2.
To change the default settings, connect the GPS16X-HVS to a computer.
Either use the A200 interface to connect to a computer USB port or the
DB9-Female-to-Terminal-Block interface to connect to a computer serial port
(see Appendix A, Changing GPS16X-HVS Settings (p. A-1)).
TABLE 6-1. Data Logger Wiring
GPS16X-HVS Data Logger Function
Red 12V Power In
Black G Power Ground
Yellow Gor C(control terminal) Ground or
Power Switch
White Cor Uconfigured for Rx1TXD
Gray Cor Uconfigured for Tx or PPS1RXD or PPS
Blue GGround
Shield
⏚
Shield
1Uterminals are automatically configured by the measurement instruction.
FIGURE 6-1. CR1000 to GPS16X-HVS connection

GPS16X-HVS GPS Receiver
8
TABLE 6-2. CR9000X Wiring
GPS16X-HVS CR9000X Function
Red 12 V (SDM or 9011
connector) Power In
Black Ground (SDM or 9011
connector)* Power Ground
Yellow Ground (SDM or 9011
connector)* Power Switch
White RS-232 pin 3 (using
28841) TXD
Gray RS-232 pin 9 (using
28841) PPS
Blue No Connection N/A
Shield Ground (SDM or 9011
connector)* Shield
*All of the grounds to the RS-232 pin 5 (using the DB9-Male-to-Terminal Block
interface). A 5-position terminal connector can be used to facilitate connecting all of the
wires into the same terminal.
6.1.1 Using with an A300
In 2014, Garmin changed the pulse-per-second (PPS) output of the
GPS16X-HVS from 5 V to 3 V. Units with a serial number 1A4189318 or
greater have a PPS output of 0 to 3 V. For those units, an A300 is needed to
connect the PPS output to a CR800-series, CR3000, or CR1000 data logger.
Those data loggers require the PPS line to have a voltage of 3.8 V or greater.
TABLE 6-3. GPS16X-HVS Wiring to A300 Terminals
and Data Logger Terminals
GPS16X-HVS
Wire Color
GPS16X-HVS
Wire Function
A300
Terminal Data Logger
Red 12 V 12V
Black Ground G
Yellow Enable Gor Cterminal
White TXD (Output) C(even) (Rx)
Gray PPS 3.3V IN
Blue Ground Ground
Shield Shield Ground

GPS16X-HVS GPS Receiver
9
TABLE 6-4. A300 Cable Wiring to Data Logger Terminals
A300 Wire Color
A300 Wire Function
Data Logger
Red 12 V 12V
Black Ground
G
Green 5 V Signal Input
G
White 5 V Signal Output C(Tx)
6.2 Mounting
The GPS16X-HVS mounts to a mast or crossarm using the CM235 Magnetic
Mounting Stand. Typically, the GPS16X-HVS mounts to the CM235
magnetically with the Magnetic Mount. Alternatively, the GPS16X-HVS can
be mounted directly to the CM235 using three M4 screws supplied with the
17212 or by the customer.
FIGURE 6-2. GPS16X-HVS mounted using a CM235 Magnetic
Mounting Stand
7. GPS Data
The GPS16X-HVS has several data formats available. The GPS16X-HVS is
configured to output the NMEA $GPGGA and $GPRMC time and position
string. It is possible to configure the GPS16X-HVS to output other NMEA
strings including the $GPVTG track made good and ground speed string. See
Appendix A, Changing GPS16X-HVS Settings (p. A-1), for details.

GPS16X-HVS GPS Receiver
10
7.1 $GPGGA Sentence (Position and Time)
Sample NMEA $GPGGA data string:
$GPGGA,hhmmss,llll.lll,a,nnnnn.nnn,b,t,uu,v.v,w.w,M,x.x,M,y.y,zzzz*hh<CR><LF>
TABLE 7-1. NMEA $GPGGA String Definition
Field Description
0 $GPGGA NMEA string identifier
1 hhmmss UTC of Position: Hours, minutes, seconds
2 1111.111 Latitude: Degrees, minutes, thousandths of minutes
3 a N (North) or S (South)
4 nnnnn.nnn Longitude: Degrees, minutes, thousandths of minutes
5 b E (East) or W (West)
6 t GPS Quality Indicator: 0 = No GPS, 1 = GPS, 2 =
DGPS
7 uu Number of Satellites in Use
8 v.v Horizontal Dilution of Precision (HDOP)
9 w.w Antenna Altitude in Meters
10 M M = Meters
11 x.x Geoidal Separation in Meters
12 M
M = Meters. Geoidal separation is the difference
between the WGS-84 earth ellipsoid and mean-sea-
level.
13 y.y Age of Differential GPS Data. Time in seconds since
the last Type 1 or 9 Update
14 zzzz Differential Reference Station ID (0000 to 1023)
15 * Asterisk, generally used as the termination character
16 hh Checksum
17 <CR><LF> Carriage return, line feed characters.
Sample $GPGGA output strings:
Cold Start
No satellites acquired, Real Time Clock and Almanac invalid:
$GPGGA,,,,,,0,00,,,,,,,*66
Warm Start
No satellites acquired, time from Real Time Clock, almanac valid:
$GPGGA,235032.0,,,,,0,00,,,,,,,*7D
Warm Start
One satellite in use, time from GPS Real Time Clock (not GPS), no position:
$GPGGA,183806.0,,,,,0,01,,,,,,,*7D

GPS16X-HVS GPS Receiver
11
Valid GPS Fix
Three satellites acquired, time and position valid:
$GPGGA,005322.0,4147.603,N,11150.978,W,1,03,11.9,00016,M,-016,M,,*6E
7.2 $GPRMC Sentence (Position and Time)
Example (signal not acquired):
$GPRMC,235947.000,V,0000.0000,N,00000.0000,E,,,041299,,*1D
Example (signal acquired):
$GPRMC,092204.999,A,4250.5589,S,14718.5084,E,0.00,89.68,211200,,*25
Field Example Comments
Sentence ID $GPRMC
UTC Time 092204.999 hhmmss.sss
Status A A = Valid, V = Invalid
Latitude 4250.5589 ddmm.mmmm
N/S Indicator S N = North, S = South
Longitude 14718.5084 dddmm.mmmm
E/W Indicator E E = East, W = West
Speed over ground 0.00 Knots
Course over ground 0.00 Degrees
UTC Date 211200 DDMMYY
Magnetic variation Degrees
Magnetic variation E = East, W = West
Checksum *25
Terminator CR/LF
8. CRBasic Programming
This section describes programming a CR6-series, CR3000, CR1000X,
CR800-series, CR300-series, CR1000, or CR9000X data logger.
8.1 GPS() Instruction
The GPS() instruction is used along with a GPS device to set the data logger
clock. This instruction will also provide information such as location
(latitude/longitude) and speed, and store NMEA sentences from the GPS
device.
To use the GPS() instruction, the data logger operating system
(OS) should be OS17 or higher for the CR1000; OS10 or higher
for the CR3000; or OS08 or higher for the CR800 series. Go to
www.campbellsci.com/downloads to upgrade the data logger OS.
NOTE

GPS16X-HVS GPS Receiver
12
The resolution of accuracy for the clock set is typically 10 microseconds. Some
older CR3000, CR800-series, and CR1000 data loggers (hardware revision
number less than or equal to 007 in RevBoard field in the data logger Status
table) have a resolution of 10 milliseconds. The clock set relies on information
from the GPRMC sentence. If this sentence is not returned, a clock set will not
occur.
By default, the instruction expects the GPS unit to be set up at 38400 baud,
outputting the GPRMC and GPGGA sentences once per second. The data
logger expects the start of the second to coincide with the rising edge of the
PPS signal. If there is no PPS signal or if the required sentences come out at
less than once per second, the data logger will not update its clock.
GPS units with lower baud rates can be used with the GPS() instruction but the
baud rate has to be set for the relevant Com port it is to be connected to either
in the data logger settings or by including a SetStatus() command after the
BeginProg() instruction in the program (for example,
SetStatus("BaudrateCOM4",19200)).
Baud rates of 2400 bps or lower will not work as the GPS unit will not transmit
the two GPS sentences once per second reliably. Similar problems can be
encountered even at higher baud rates if too many optional GPS strings are
selected to be output.
The GPS() instruction has the following syntax:
GPS(GPSArray,ComPort,TimeOffset,MaxTimeDiff,NMEAStrings)
Description of the parameters follows:
GPSArray The GPSArray parameter is the variable in which to store the
information returned by the GPS. Fifteen values are returned.
If this array is not dimensioned to 15, values will be stored to
fill the array and no error will be returned. If no values are
available, NAN will be returned. The following values are
returned by the GPS:
Array(1) = Latitude, degrees
Array(2) = Latitude, minutes
Array(3) = Longitude, degrees
Array(4) = Longitude, minutes
Array(5) = Speed over ground, knots
Array(6) = Course over ground, degrees
Array(7) = Magnetic variation (positive = East, negative =
West)
Array(8) = Fix Quality (0 = invalid, 1 = GPS, 2 = differential
GPS, 6 = estimated)
Array(9) = Number of Satellites
Array(10) = Altitude, meters
Array(11) = Pulse per second (PPS) length, microseconds
Array(12) = Seconds since last GPRMC sentence
Array(13) = GPS Ready, 10 = ready
Array(14) = Maximum clock change, milliseconds (10 msec
resolution)
Array(15) = Clock change count

GPS16X-HVS GPS Receiver
13
ComPort The ComPort parameter is the control terminal pair to which
the GPS device is attached. Valid options are COM1 (C1/C2),
COM2 (C3/C4), COM3 (C5/C6), and COM4 (C7/C8). Rx is
used to read in the NMEA sentences and Tx is used to monitor
the PPS from the GPS. This instruction defaults to a baud rate
of 38,400 bps. If a different baud rate is required, use the
SetStatus() instruction to override the default.
TimeOffset The TimeOffset parameter is the local time offset, in seconds,
from UTC.
MaxTimeDiff The MaxTimeDiff parameter is the maximum difference in
time between the data logger clock and the GPS clock that will
be tolerated before the clock is changed. If a negative value is
entered, the clock will not be changed.
For data loggers prior to hardware revision 08, the
MaxTimeDiff parameter should not be set to 0. A minimum
value of 20 ms is recommended. With this hardware, when a
GPS() instruction is in the program the clock is checked each
second (regardless of how often the GPS() instruction is run).
The clock is set if any difference is found. This can result in
the clock being set each second, resulting in skipped records in
the data table(s). This restriction does not apply to hardware
revisions 08 or greater.
NMEAStrings The NMEAStrings parameter is the string array that holds the
NMEA sentences. If it exists, the GPRMC sentence will reside
in NMEAStrings(1), and the GPGGA sentence will reside in
NMEAStrings(2). Any other sentences will reside in
subsequent indexes into the array (on a first-in basis). Once an
index in the array is used to store a particular sentence, that
sentence will always be stored in that location when updates to
the sentence are received.
8.2 Example Program Using GPS() Instruction
The following wiring and short program provide an example of using the
GPS() instruction with the Garmin GPS16X-HVS.

GPS16X-HVS GPS Receiver
14
CRBasic Example 8-1. Reading the GPS Using the GPS() Instruction
'Program the GPS16-HVS to use 38.4 kbaud, no parity, 8 data bits, and 1 stop bit
PipeLineMode
Const LOCAL_TIME_OFFSET = -6 'Local time offset relative to UTC time
Dim nmea_sentence(2) As String * 100
Public gps_data(15)
Alias gps_data(1) = latitude_a 'Degrees latitude (+ = North; - = South)
Alias gps_data(2) = latitude_b 'Minutes latitude
Alias gps_data(3) = longitude_a 'Degress longitude (+ = East; - = West)
Alias gps_data(4) = longitude_b 'Minutes longitude
Alias gps_data(5) = speed 'Speed
Alias gps_data(6) = course 'Course over ground
Alias gps_data(7) = magnetic_variation 'Magnetic variation from true north (+ =
'East; - = West)
Alias gps_data(8) = fix_quality 'GPS fix quality: 0 = invalid, 1 = GPS, 2 =
'differential GPS, 6 = estimated
Alias gps_data(9) = nmbr_satellites 'Number of satellites used for fix
Alias gps_data(10) = altitude 'Antenna altitude
Alias gps_data(11) = pps 'usec into sec of system clock when PPS
'rising edge occurs, typically 990,000 once
'synced
Alias gps_data(12) = dt_since_gprmc 'Time since last GPRMC string, normally less
'than 1 second
Alias gps_data(13) = gps_ready 'Counts from 0 to 10, 10 = ready
Alias gps_data(14) = max_clock_change 'Maximum value the clock was changed in msec
Alias gps_data(15) = nmbr_clock_change 'Number of times the clock was changed
'Define Units to be used in data file header
Units latitude_a = degrees
Units latitude_b = minutes
Units longitude_a = degrees
Units longitude_b = minutes
Units speed = knots
Units course = degrees
Units magnetic_variation = unitless
Units fix_quality = unitless
Units nmbr_satellites = unitless
Units altitude = m
Units pps = ms
Units dt_since_gprmc = s
Units gps_ready = unitless
Units max_clock_change = ms
Units nmbr_clock_change = samples
BeginProg
'Use SetStatus prior to scan if baud rate needs to be changed for device
Scan (1,Sec,0,0)
GPS (latitude_a,Com4,LOCAL_TIME_OFFSET*3600,100,nmea_sentence(1))
NextScan
EndProg
9. Troubleshooting
Testing and evaluation of serial communications is best done by reducing the
whole system to small manageable systems. Usually some portions of the
whole system are working. The first steps involve finding what is working.
During this process, you may find parts of the system that are not working or
mistakes that can be easily corrected. Fix each subsystem before testing others.

GPS16X-HVS GPS Receiver
15
9.1 Testing and Evaluating Serial Communications
9.1.1 Through a Direct Connection to the GPS16X-HVS
Test the GPS16X-HVS for proper operation including the baud rate and output
string. Use a computer, terminal emulator software, a serial port (RS-232), and
a DB9 to Terminal Block Interface. The computer and serial port can be the
same as used to communicate with the data logger. Terminal emulation
software is common. Hyperterm is supplied as part of Windows™ and works.
Procomm™ is another communication software package that works well.
Set up the software for the correct serial port, 38.4 kbps, 8 data bits, 1 stop bit
and no parity. Flow control should be none. Using the DB9-Female-to-Terminal-
Block interface, connect the GPS16X-HVS to the computer serial port. Power up
the GPS16X-HVS. The GPS antenna should have a clear view of the sky. Don’t
expect the GPS antenna to work indoors. The $GPGGA and GPRMC strings
should be displayed once a second. Make sure the $GPGGA string is showing a
valid GPS fix. A valid GPS fix will display time, position and have a GPS
quality number greater than zero.
DB9-Female-to-Terminal-Block Connections
GPS16X Receiver DB9 to Terminal Block Interface
White Pin 2
Black and Yellow Pin 5 (shares power ground)
9.1.2 Through a Data Logger Connected to the GPS16X-HVS
Serial communication can also be tested using the data logger terminal mode
watch command, also known as sniffer mode. To enter sniffer mode:
1. Connect to your data logger in the Device Configuration Utility and select
the Terminal tab. (You can also use the Terminal Emulator in PC200W,
PC400, or the LoggerNet Connect screen.)
2. Press Enter until a datalogger_type> prompt (for example, CR1000X>)
appears.
3. Type Wand press Enter.
4. In response, the query Select: is presented with a list of available
terminals. Enter the port number assigned to the terminal to which the
GPS16X-HVS is connected, and press Enter.
5. In answer to Enter timeout (secs):, type 100 and press Enter.
6. In response to the query ASCII (Y)?, type Yand press Enter.
7. Communication between the data logger and GPS16X-HVS is now open
for viewing.
If you see no communication, the GPS16X-HVS is hooked up incorrectly, is
not powered, or does not have the yellow wire tied to ground. If you see
readable NMEA strings coming in but many fields are not populated, you most

GPS16X-HVS GPS Receiver
16
likely need to go outside to obtain a better signal. If you see “garbage”
characters coming in (that is, non-NMEA strings), there is likely a baud rate
mismatch.
9.2 NMEAStrings Variable Populated, but Clock Not Setting
Look at the GPSReady variable. It will increment from 0 to 10 when the data
logger has received good GPRMC strings and a synchronized PPS signal. Once
GPSReady reaches 10, the data logger will begin to use GPS time for clock
setting. The 12th value populated in GPSArray indicates elapsed time since a
GPRMC string was received and should not exceed 1. If the GPRMC string is
being received and GPSReady remains at zero, the PPS signal is not being
received by the data logger.

A-1
Appendix A. Changing GPS16X-HVS
Settings
As configured by Campbell Scientific, the GPS16X-HVS will output the
NMEA 0183 $GPGGA and $GPRMC data strings once a second, the PPS
signal is enabled with a duration of 100 milliseconds and the baud rate is set to
38,400 baud.
Special software (SNRSRCFG.EXE) is available from Garmin International
for system setup. The GPS16X-HVS user manual available from Garmin
International provides technical details beyond the scope of the Campbell
Scientific user manual.
Settings used by Campbell Scientific for GPS16X-HVS setup:
GPS Base Model = GPS 16(X)
Fix Mode = Automatic
Baud Rate = 38,400
Dead Reckon Time = 30 sec
NMEA output time = 1 sec
Position pinning = off
NMEA 2.30 mode = off
Power Save Mode = off (Normal mode)
PPS mode = 1 Hz
PPS Length = 100 mS
Phaze output Data = off
DGPS Mode = WAAS only
Differential mode = Automatic
Earth Datum Index = WGS 84
Selected Sentences = GPGGA and GPRMC
Common changes would be baud rate and selected sentences. The NMEA 0183
GPVTG data sentence gives ground speed and direction, which may be
required for some applications. Changes can be made with the Garmin
software, or with a terminal emulator and the Garmin technical user manual.
Contact Garmin International (www.garmin.com) for either resource.
A.1 Computer Connections
Either an A200 interface or a DB9-Female-to-Terminal-Block interface is
required to connect the GPS16X-HVS to a computer. The A200 is used to
connect to a computer USB port, and the DB9 Female to Terminal Block is
used to connect to a computer 9-pin serial port.
A.1.1 Using the A200
A.1.1.1 Driver Installation
If the A200 has not been previously plugged into your computer, the A200
driver needs to be loaded onto your computer.