Airmar | LB150 | Specifications | Airmar LB150 Specifications

LB150 WeatherStation Technical Manual revision 0.013
Proprietary and Confidential
LB150 WeatherStation Technical Manual
Revision 0.013
08/07/08
- DRAFT This document is PRELIMINARY and Subject to Change.
AIRMAR Technology Corporation
35 Meadowbrook Drive
Milford, NH 03055-4613
(603) 673-9570
PROPRIETARY AND CONFIDENTIAL
THIS DOCUMENT AND THE DATA DISCLOSED HEREIN OR
HEREWITH IS NOT TO BE REPRODUCED, USED, OR DISCLOSED
IN WHOLE OR IN PART TO ANYONE WITHOUT THE
PERMISSION OF AIRMAR TECHNOLOGY CORPORATION.
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Table of Contents
1.
Introduction............................................................................................................. 1
2.
NMEA 0183 Interfaces ........................................................................................... 2
2.1.
Transmitted NMEA 0183 Sentences .................................................................. 2
$GPDTM............................................................................................................. 5
$GPGGA............................................................................................................. 7
$GPGLL.............................................................................................................. 9
$GPGSA ........................................................................................................... 10
$GPGSV ........................................................................................................... 11
$HCHDG .......................................................................................................... 13
$HCHDT........................................................................................................... 14
$WIMDA .......................................................................................................... 15
$WIMWD ......................................................................................................... 17
$WIMWV ......................................................................................................... 18
$GPRMC........................................................................................................... 20
$GPVTG ........................................................................................................... 22
$WIVWR .......................................................................................................... 23
$WIVWT .......................................................................................................... 24
$YXXDR .......................................................................................................... 25
$GPZDA ........................................................................................................... 28
2.2. Received NMEA 0183 Sentences and Commands........................................... 29
2.2.1.
Precedence of Data ................................................................................... 29
$--HDG ............................................................................................................. 31
$--HDT.............................................................................................................. 32
$--VHW ............................................................................................................ 33
$PAMTC........................................................................................................... 34
$PAMTC,ALT .................................................................................................. 35
$PAMTC,ATTOFF........................................................................................... 37
$PAMTC,BAUD .............................................................................................. 40
$PAMTC,COMP .............................................................................................. 41
$PAMTC,DATUM ........................................................................................... 48
$PAMTC,EN .................................................................................................... 50
$PAMTC,ERST................................................................................................ 55
$PAMTC,HEATER .......................................................................................... 56
$PAMTC,OPTION ........................................................................................... 57
$PAMTC,POST................................................................................................ 61
$PAMTC,QPS .................................................................................................. 63
$PAMTC,QV .................................................................................................... 64
$PAMTC,RESET.............................................................................................. 65
$PAMTC,SIM................................................................................................... 66
$PAMTX........................................................................................................... 67
3.
Revision History ................................................................................................... 68
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1.
Introduction
This document is a supplement to the Airmar LB150 WeatherStation Owner's Guide.
The LB150 WeatherStation is a multifunctional device that integrates several sensors into a single
compact housing. These sensors include:
• Ultrasonic anemometer, providing apparent wind speed and direction
• Thermistor, providing air temperature
• Capacitive humidity sensor, providing % relative humidity
• Piezoresistive pressure sensor, providing barometric pressure
• Magnetoinductive XY sensors, providing magnetic compass heading
• 3-axis MEMS1 accelerometer, providing pitch and roll angles
• Global Positioning System (GPS) receiver, providing position, and speed and course over ground
In addition to the above directly measured parameters, the LB150 WeatherStation is able to calculate the
following values as well, if the necessary data are available:
• True wind speed and direction
• Heading relative to true north
• Dew point
• Apparent wind chill temperature
• True wind chill temperature
• True wind speed relative to water (with optional Airmar® Smart™ speed sensor, not included)
The LB150 WeatherStation provides one communication interface compliant with the NMEA 0183
protocol
This document provides detailed descriptions of the communications protocol for the NMEA 0183
interface used by the LB150 WeatherStation.
For further information about the NMEA 0183 protocol, refer to the document, NMEA 0183 Standard
for Interfacing Marine Electronic Devices, v3.01. This document is available from the National Marine
Electronics Association (www.nmea.org).
1
MEMS is an acronym for Micro Electro-Mechanical Systems
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2.
NMEA 0183 Interfaces
The Airmar LB150 WeatherStation has a single standard NMEA 0183-compliant output
channel, and a single standard NMEA 0183-compliant input channel. The unit transmits
standard NMEA 0183 sentences on its output channel. It also recognizes standard and
proprietary NMEA 0183 sentences received on its input channel. The standard baud rate
for both input and output channels is 4800 baud, though if desired this may be increased
to 38400 baud via a proprietary command.1
The transmitted NMEA 0183 sentences are described in section 2.1. Received NMEA
0183 sentences and proprietary commands are described in section 2.2.
2.1.
Transmitted NMEA 0183 Sentences
By default, only certain NMEA sentences are enabled for transmission. Other sentences
may be enabled individually for transmission via commands sent to the input channel.2
The standard transmission interval for most of the transmitted sentences is once per
second. However, in models that include an integrated GPS, if every sentence were
enabled for transmission, there would not be enough bandwidth in the output channel at
4800 baud to output all sentences within a one second timeframe. Therefore, one or more
of the following remedies should be employed:
•
To conserve bandwidth, only enable for transmission those sentences required for
the given application, and disable all others.
•
Reduce the frequency of transmission for less critical sentences.
•
Increase the overall bandwidth eightfold by increasing the baud rate from the
standard 4800 baud to 38400 baud (though keep in mind that most NMEA 0183
instruments are not capable of operating at 38400 baud)
All NMEA sentences transmitted by the LB150 WeatherStation include a checksum at
the end of the sentence, consisting of an asterisk (*) followed by two ASCII hexadecimal
characters. In the detailed specifications to follow, these hexadecimal characters are
designated by “hh”.
The standard NMEA 0183 sentences provided by the LB150 WeatherStation are
summarized in Table 1. Each of the transmitted sentences in Table 1 is described in
detail on the subsequent pages.
1
2
See the $PAMTC,BAUD command.
See the $PAMTC,EN command.
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The Maximum Length (chars) column in the table indicates an expected worst-case
scenario that can be used for bandwidth budgeting. The total time in seconds required to
transmit all enabled sentences in a single interval is
Total _ transmission _ time =
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Total _ number _ of _ characters × 10
baud _ rate
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Table 1: NMEA 0183 Regularly Transmitted Sentences
Description
Sentence
Enabled
by Default
Maximum
Length
(chars)
No
47
$GPDTM
Datum Reference
$GPGGA
GPS Fix Data
$GPGLL
Geographic Position – Latitude/Longitude
No
48
$GPGSA
GNSS DOP and Active Satellites
No
66
$GPGSV
GNSS Satellites in View
No
70
$HCHDG
Heading, Deviation and Variation
No
33
$HCHDT
Heading relative to True North
19
$WIMDA
Meteorological Composite.
Barometric pressure, air temperature,
relative humidity, dew point, wind direction,
wind speed
81
$WIMWD
Wind Direction and Speed, with respect to
north1
$WIMWV
(relative)
Wind Speed and Angle, in relation to the
centerline of the front of the vehicle
(relative)
$WIMWV
(theoretical)
Wind Speed and Angle, in relation to the
centerline of the front of the vehicle
(theoretical) 1
No
28
$GPRMC
Recommended Minimum Specific GNSS
Data
No
74
$GPVTG
Course Over Ground and Ground Speed
$WIVWR
Relative Wind Speed and Angle
82
No
41
28
42
No
No
2
41
$WIVWT
True Wind Speed and Angle
41
$YXXDR
(type A)
Transducer Measurements: wind chill, heat
index, and station pressure
74
$YXXDR
(type B)
Transducer Measurements:
vehicle/instrument attitude (pitch and roll)
43
$GPZDA
Time and Date
38
1
True wind data is provided in the $WIMWD and $WIMWV (theoretical) sentences if SOG/COG,
heading, and magnetic variation data are available from the internal GPS and compass.
2
$WIVWT True Wind Speed and Angle referenced to water is provided only if water referenced speed is
available via the NMEA 0183 input from an Airmar® Smart™ speed sensor.
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NMEA 0183 TRANSMITTED SENTENCE
$GPDTM
Summary
NMEA 0183 standard Datum Reference.
Syntax
Fields
$GPDTM,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>*hh<CR><LF>
<1>
Three character alphabetical code for local datum:
W84 (WGS84)
W72 (WGS72)
S85 (SGS85)
P90 (PE90)
or IHO datum code from the International Hydrographic
Organization Publication S-60 Appendices B and C.
<2>
One character subdivision datum code when available, as defined in
IHO Publication S-60 Appendices B and C.
<3>
Latitude offset, to the nearest .0001 minute
<4>
N if field <3> is North Latitude
S if field <3> is South Latitude
<5>
Longitude offset, to the nearest .0001 minute
<6>
E if field <5> is East Longitude
W if field <5> is West Longitude
<7>
Signed altitude offset, to the nearest meter
<8>
3-character reference datum code:
W84 = WGS-84
Default State
Disabled. Transmitted once per second when enabled.
Notes
This sentence may be enabled or disabled via the $PAMTC,EN,DTM command.
Latitude and longitude offsets are positive numbers; the altitude offset may be
negative. Offsets change with position; position in the local datum is offset from
the position in the reference datum in the directions indicated:
Plocal datum = Pref datum + offset
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KGS, OHI-A, OHI-B, OHI-C, OHI-D, OHI-M, SIR, P90, and S85 are not
currently supported by the GPS Engine used in the LB150, and therefore are not
available for use as Local Datum.
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NMEA 0183 TRANSMITTED SENTENCE
$GPGGA
Summary
NMEA 0183 standard GPS Fix Data.
Syntax
Fields
$GPGGA,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,
<9>,<10>,<11>,<12>,<13>,<14>*hh<CR><LF>
<1>
UTC of position, in the form hhmmss
<2>
Latitude, to the nearest .0001 minute
<3>
N if field <2> is North Latitude
S if field <2> is South Latitude
<4>
Longitude, to the nearest .0001 minute
<5>
E if field <4> is East Longitude
W if field <4> is West Longitude
<6>
GPS quality indicator:
0 = Fix not available or invalid
1 = GPS SPS Mode, fix valid
2 = Differential GPS, SPS Mode, fix valid
3 = GPS PPS Mode, fix valid
4 = Real Time Kinematic (RTK)
5 = Float RTK
6 = Estimated (dead reckoning) Mode
7 = Manual Input Mode
8 = Simulator Mode
When providing data from the LB150 WeatherStation’s internal GPS,
the only valid values for the GPS quality indicator are 0, 1, and 2.
<7>
Number of satellites in use, 0-12
<8>
Horizontal dilution of precision (HDOP)
<9>
Altitude relative to mean-sea-level (geoid), meters (to the nearest
whole meter)
<10>
M
<11>
Geoidal separation, meters (to the nearest whole meter). This field is
not provided by the LB150 WeatherStation, and appears as a null field.
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<12>
M. This field is not provided by the LB150 WeatherStation, and
appears as a null field.
<13>
Age of Differential GPS data, seconds. This field is not provided by the
LB150 WeatherStation, and appears as a null field.
<14>
Differential reference station ID, 0000-1023. This field is not provided
by the LB150 WeatherStation, and appears as a null field.
Default State
Enabled. Transmitted once per second.
Notes
This sentence may be enabled or disabled via the $PAMTC,EN,GGA command.
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NMEA 0183 TRANSMITTED SENTENCE
$GPGLL
Summary
NMEA 0183 standard Geographic Position – Latitude/Longitude.
Syntax
Fields
$GPGLL,<1>,<2>,<3>,<4>,<5>,<6>,<7>*hh<CR><LF>
<1>
Latitude, to the nearest .0001 minute
<2>
N if field <1> is North Latitude
S if field <1> is South Latitude
<3>
Longitude, to the nearest .0001 minute
<4>
E if field <3> is East Longitude
W if field <3> is West Longitude
<5>
UTC of position, in the form hhmmss
<6>
Status:
<7>
A = data valid; V = data invalid
Mode indicator:
A = Autonomous mode
D = Differential mode
E = Estimated (dead reckoning) mode
M = Manual input mode
S = Simulator mode
N = Data not valid
The only values transmitted by the LB150 WeatherStation for the
Mode indicator are A, D, and N.
Default State
Disabled. Transmitted once per second when enabled.
Notes
This sentence may be enabled via the $PAMTC,EN,GLL command.
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NMEA 0183 TRANSMITTED SENTENCE
$GPGSA
Summary
NMEA 0183 standard GNSS DOP and Active Satellites.
Syntax
Fields
$GPGSA,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,
<12>,<13>,<14>,<15>,<16>,<17>*hh<CR><LF>
<1>
M = Manual, forced to operate in 2D or 3D mode
A = Automatic, allowed to automatically switch 2D/3D
<2>
1 = Fix not available
2 = 2D fix
3 = 3D fix
<3>-<14>
ID numbers of satellites used in solution
<15>
Positional Dilution of Precision (PDOP). This field is null unless
the GPS has a 3D fix.
<16>
Horizontal Dilution of Precision (HDOP). This field is null unless
the GPS has either a 2D fix or a 3D fix.
<17>
Vertical Dilution of Precision (VDOP). This field is null unless
the GPS has a 3D fix.
Default State
Disabled. Transmitted once per second when enabled.
Notes
This sentence may be enabled via the $PAMTC,EN,GSA command.
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NMEA 0183 TRANSMITTED SENTENCE
$GPGSV
Summary
NMEA 0183 standard GNSS Satellites in View.
Syntax
Fields
$GPGSV,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,
<12>,<13>,<14>,<15>,<16>,<17>,<18>,<19>*hh<CR><LF>
<1>
Total number of GSV sentences (1 to 3 for internal GPS in LB150
WeatherStation)
<2>
Sentence number (1, 2, or 3)
<3>
Total number of satellites in view
<4>
Satellite ID number, 1st SV
<5>
Elevation degrees, 0 to 90, to the nearest degree, 1st SV
<6>
Azimuth, degrees True, to the nearest degree, 1st SV
<7>
SNR (C/No) 00-99 dB-Hz, 1st SV (null field if satellite not tracked)
<8>
Satellite ID number, 2nd SV
<9>
Elevation degrees, 0 to 90, to the nearest degree, 2nd SV
<10>
Azimuth, degrees True, to the nearest degree, 2nd SV
<11>
SNR (C/No) 00-99 dB-Hz, 2nd SV (null field if satellite not tracked)
<12>
Satellite ID number, 3rd SV
<13>
Elevation degrees, 0 to 90, to the nearest degree, 3rd SV
<14>
Azimuth, degrees True, to the nearest degree, 3rd SV
<15>
SNR (C/No) 00-99 dB-Hz, 3rd SV (null field if satellite not tracked)
<16>
Satellite ID number, 4th SV
<17>
Elevation degrees, 0 to 90, to the nearest degree, 4th SV
<18>
Azimuth, degrees True, to the nearest degree, 4th SV
<19>
SNR (C/No) 00-99 dB-Hz, 4th SV (null field if satellite not tracked)
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Default State
Disabled. Transmitted once per second when enabled. This sentence is
transmitted in groups of up to three instances, containing data for up to 4 satellites
with each instance, for a total of up to 12 satellites. Fields <1> and <3> only
contain data in the first instance; they are null fields in the second and third
instances.
Notes
This sentence may be enabled via the $PAMTC,EN,GSV command.
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NMEA 0183 TRANSMITTED SENTENCE
$HCHDG
Summary
NMEA 0183 standard Heading, Deviation and Variation.
Syntax
Fields
$HCHDG,<1>,<2>,<3>,<4>,<5>*hh<CR><LF>
<1>
Magnetic sensor heading, degrees, to the nearest 0.1 degree.
<2>
Magnetic deviation, degrees east or west, to the nearest 0.1 degree.
<3>
E if field <2> is degrees East
W if field <2> is degrees West
<4>
Magnetic variation, degrees east or west, to the nearest 0.1 degree.
<5>
E if field <4> is degrees East
W if field <4> is degrees West
Default State
Disabled. Transmitted twice per second when enabled.
Notes
This sentence may be enabled or disabled via the $PAMTC,EN,HDG command.
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NMEA 0183 TRANSMITTED SENTENCE
$HCHDT
Summary
NMEA 0183 standard Heading relative to True North
Syntax
Fields
$HCHDT,<1>,<2>*hh<CR><LF>
<1>
Heading relative to True North
<2>
T = True
Default State
Enabled. Transmitted twice per second.
Notes
This sentence may be enabled or disabled via the $PAMTC,EN,HDT command.
The data in field <1> is only provided if both magnetic compass heading and
magnetic variation values are available.
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NMEA 0183 TRANSMITTED SENTENCE
$WIMDA
Summary
NMEA 0183 standard Meteorological Composite.
Syntax
Fields
$WIMDA,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,
<12>,<13>,<14>,<15>,<16>,<17>,<18>,<19>,<20>*hh
<CR><LF>
<1>
Barometric pressure, inches of mercury, to the nearest 0.01 inch
<2>
I = inches of mercury
<3>
Barometric pressure, bars, to the nearest .001 bar
<4>
B = bars
<5>
Air temperature, degrees C, to the nearest 0.1 degree C
<6>
C = degrees C
<7>
Water temperature, degrees C (this field left blank by WeatherStation)
<8>
C = degrees C (this field left blank by WeatherStation)
<9>
Relative humidity, percent, to the nearest 0.1 percent
<10>
Absolute humidity, percent (this field left blank by WeatherStation)
<11>
Dew point, degrees C, to the nearest 0.1 degree C
<12>
C = degrees C
<13>
Wind direction, degrees True, to the nearest 0.1 degree
<14>
T = true
<15>
Wind direction, degrees Magnetic, to the nearest 0.1 degree
<16>
M = magnetic
<17>
Wind speed, knots, to the nearest 0.1 knot
<18>
N = knots
<19>
Wind speed, meters per second, to the nearest 0.1 m/s
<20>
M = meters per second
Default State
Enabled. Transmitted once per second.
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Notes
This sentence may be enabled or disabled via the $PAMTC,EN,MDA command.
The barometric pressure provided in this sentence is the altimeter setting, which is
the barometric pressure corrected for altitude above sea level. See the transmitted
$YXXDR(A) sentence, and the received $PAMTC,ALT command, for further
information.
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NMEA 0183 TRANSMITTED SENTENCE
$WIMWD
Summary
NMEA 0183 standard Wind Direction and Speed, with respect to north.
Syntax
Fields
$WIMWD,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>*hh<CR><LF>
<1>
Wind direction, 0.0 to 359.9 degrees True, to the nearest 0.1 degree
<2>
T = True
<3>
Wind direction, 0.0 to 359.9 degrees Magnetic, to the nearest 0.1
degree
<4>
M = Magnetic
<5>
Wind speed, knots, to the nearest 0.1 knot.
<6>
N = Knots
<7>
Wind speed, meters/second, to the nearest 0.1 m/s.
<8>
M = Meters/second
Default State
Disabled. Transmitted once per second when enabled.
Notes
The wind speed and direction data provided in this sentence are calculated using
vector math based on the measured apparent wind speed and direction, SOG and
COG from the GPS, compass heading, and magnetic variation. If any of these
data are not available, this sentence shall be transmitted with null fields.
This sentence may be enabled or disabled via the $PAMTC,EN,MWD command.
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NMEA 0183 TRANSMITTED SENTENCE
$WIMWV
Summary
NMEA 0183 standard Wind Speed and Angle, in relation to the centerline of the
front of the vehicle.
Syntax
Fields
$WIMWV,<1>,<2>,<3>,<4>,<5>*hh<CR><LF>
<1>
Wind angle, 0.0 to 359.9 degrees, in relation to the centerline of the
front of the vehicle, to the nearest 0.1 degree. If the data for this field
is not valid, the field will be blank.
<2>
Reference:
R = Relative (apparent wind, as felt when standing on the
moving vehicle)
T = Theoretical (calculated actual wind, as though the vehicle
were stationary)
<3>
Wind speed, to the nearest tenth of a unit. If the data for this field is
not valid, the field will be blank.
<4>
Wind speed units:
K = km/hr
M = m/s
N = knots
S = statute miles/hr
In the LB150 WeatherStation, this field always contains "N" (knots).
<5>
Status:
A = data valid; V = data invalid
Default State
MWV(R): Enabled. Transmitted twice per second.
MWV(T): Disabled. Transmitted once per second when enabled.
Notes
Depending on the contents of the Reference field (field <2>), this sentence
provides either relative (apparent) wind or theoretical (true) wind data, both in
relation to the front of the vehicle. Although it is conceivable that both of these
forms could be useful simultaneously, the LB150 WeatherStation by default only
outputs this sentence once in the MWV(R) form.
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To enable/disable the theoretical (true) form of this sentence, use the
$PAMTC,EN,MWVT command. To enable/disable the relative (apparent) form,
use the $PAMTC,EN,MWVR command.
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NMEA 0183 TRANSMITTED SENTENCE
$GPRMC
Summary
NMEA 0183 standard Recommended Minimum Specific GNSS Data.
Syntax
Fields
$GPRMC,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,
<9>,<10>,<11>,<12>*hh<CR><LF>
<1>
UTC of position, in the form hhmmss
<2>
Status: A = Data Valid; V = Navigation Receiver Warning
<3>
Latitude, to the nearest .0001 minute
<4>
N if field <2> is North Latitude
S if field <2> is South Latitude
<5>
Longitude, to the nearest .0001 minute
<6>
E if field <4> is East Longitude
W if field <4> is West Longitude
<7>
Speed Over Ground, knots, to the nearest 0.1 knot
<8>
Course Over Ground, degrees True, to the nearest 0.1 degree
<9>
Date: ddmmyy
<10>
Magnetic Variation, degrees E/W, to the nearest 0.1 degree
<11>
E if field <10> is degrees East
W if field <10> is degrees West
<12>
Mode indicator:
A = Autonomous mode
D = Differential mode
E = Estimated (dead reckoning) mode
M = Manual input mode
S = Simulator mode
N = Data not valid
The only values transmitted by the LB150 WeatherStation for the
Mode indicator are A, D, and N.
Default State
Disabled. Transmitted once per second when enabled.
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Notes
This sentence may be enabled via the $PAMTC,EN,RMC command.
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NMEA 0183 TRANSMITTED SENTENCE
$GPVTG
Summary
NMEA 0183 standard Course Over Ground and Ground Speed.
Syntax
Fields
$GPVTG,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
<1>
Course Over Ground, degrees True, to the nearest 0.1 degree
<2>
T = True
<3>
Course Over Ground, degrees Magnetic, to the nearest 0.1 degree
<4>
M = Magnetic
<5>
Speed Over Ground, knots, to the nearest 0.1 knot
<6>
N = Knots
<7>
Speed Over Ground, km/hr, to the nearest 0.1 km/hr
<8>
K = km/hr
<9>
Mode indicator:
A = Autonomous mode
D = Differential mode
E = Estimated (dead reckoning) mode
M = Manual input mode
S = Simulator mode
N = Data not valid
The only values transmitted by the LB150 WeatherStation for the
Mode indicator are A, D, and N.
Default State
Enabled. Transmitted once per second.
Notes
This sentence may be enabled or disabled via the $PAMTC,EN,VTG command.
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NMEA 0183 TRANSMITTED SENTENCE
$WIVWR
Summary
NMEA 0183 Relative (Apparent) Wind Speed and Angle. For vehicle mounted
instruments, wind angle is in relation to the vehicle’s heading, and wind speed
measured relative to the moving vehicle. For stationary instruments, wind speed
and angle are relative to the sensor.
Syntax
Fields
$WIVWR,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>*hh<CR><LF>
<1>
Measured wind angle relative to the vehicle, 0 to 180°, left/right of
vehicle heading, to the nearest 0.1 degree
<2>
L = left, or R = right
<3>
Measured wind speed, knots, to the nearest 0.1 knot
<4>
N = knots
<5>
Wind speed, meters per second, to the nearest 0.1 m/s
<6>
M = meters per second
<7>
Wind speed, km/h, to the nearest km/h
<8>
K = km/h
Default State
Disabled. Transmitted once per second if enabled.
Notes
This sentence may be enabled via the $PAMTC,EN,VWR command.
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NMEA 0183 TRANSMITTED SENTENCE
$WIVWT
Summary
NMEA 0183 True wind angle in relation to the vessel’s heading, and true wind
speed referenced to the water. True wind is the vector sum of the Relative
(apparent) wind vector and the vessel’s velocity vector relative to the water along
the heading line of the vessel. It represents the wind at the vessel if it were
stationary relative to the water and heading in the same direction. Since LB150s
are not intended for use on boats, this sentence is not likely to be useful, but if
enabled and VHW sentence is received, it will work.
Syntax
Fields
$WIVWT,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>*hh<CR><LF>
<1>
Calculated wind angle relative to the vessel, 0 to 180°, left/right of
vessel heading, to the nearest 0.1 degree
<2>
L = left, or R = right
<3>
Calculated wind speed, knots, to the nearest 0.1 knot
<4>
N = knots
<5>
Wind speed, meters per second, to the nearest 0.1 m/s
<6>
M = meters per second
<7>
Wind speed, km/h, to the nearest km/h
<8>
K = km/h
Default State
Disabled, but when enabled, automatically prohibited until water speed is
provided via the NMEA 0183 input. Transmitted once per second when enabled
and not prohibited.
Notes
This sentence can be manually enabled or disabled via the $PAMTC,EN,VWT
command.
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NMEA 0183 TRANSMITTED SENTENCE
$YXXDR
Summary
NMEA 0183 Transducer Measurements. Used in the LB150 WeatherStation to
provide wind chill, heat index, barometric station pressure, and vehicle attitude
(pitch and roll) data. For stationary instruments pitch and roll indicate the
orientation in which the instrument was mounted.
IMPORTANT NOTE: See the discussion in the Notes section below regarding
the behavior of the XDR sentence with regard to null fields and commas.
Syntax
Fields
$YXXDR,<1>, <2>, <3>, <4>,
<5>, <6>, <7>, <8>,
<9>, <10>,<11>,<12>,
<13>,<14>,<15>,<16>
*hh<CR><LF>
There are two versions of this sentence, the "A" version, and the "B" version.
The fields in the A version of the XDR sentence are as follows:
<1>
C = temperature
<2>
Calculated “relative” wind chill temperature, degrees Celsius, to the
nearest 0.1 degree
<3>
C = degrees C
<4>
WCHR (ID indicating relative wind chill)
<5>
C = temperature
<6>
Calculated “theoretical” wind chill temperature, degrees Celsius, to the
nearest 0.1 degree
<7>
C = degrees C
<8>
WCHT (ID indicating theoretical wind chill)
<9>
C = temperature
<10>
Calculated heat index, degrees Celsius, to the nearest 0.1 degree
<11>
C = degrees C
<12>
HINX (ID indicating heat index)
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<13>
P = pressure
<14>
Actual measured barometric pressure, or "station pressure", bars, to the
nearest 0.001 bar
<15>
B = bars
<16>
STNP (ID indicating station pressure)
The fields in the B version of the XDR sentence are as follows:
<1>
A = angular displacement
<2>
Pitch: oscillation of vehicle about its latitudinal axis. Front of the
vehicle moving up is positive. Value reported to the nearest 0.1
degree.
<3>
D = degrees
<4>
PTCH (ID indicating pitch of vehicle)
<5>
A = angular displacement
<6>
Roll: oscillation of vehicle about its longitudinal axis. Roll to the right
is positive. Value reported to the nearest 0.1 degree.
<7>
D = degrees
<8>
ROLL (ID indicating roll of vehicle)
<9>
Not used
<10>
Not used
<11>
Not used
<12>
Not used
<13>
Not used
<14>
Not used
<15>
Not used
<16>
Not used
Default State
$YXXDR(A): Disabled. Transmitted once per second when enabled.
$YXXDR(B): Disabled. Transmitted once per second when enabled.
Notes
The fields in an XDR sentence are grouped in sets of four. There may be up to
four sets, with four fields per set, in a single transmitted XDR sentence. Each set
contains, in order, the four fields <Type>, <Data>, <Units>, and <ID>. If for
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some reason the contents of a given set are not available, then the entire set
(including commas) may be omitted.
Because there are two versions of the XDR sentence, and because a group of four
fields can be omitted entirely, it is necessary when parsing any XDR sentence to
examine the <ID> field in each set of four fields in order to identify the meaning
of the data in that set.
The XDR(A) sentence may be enabled via the $PAMTC,EN,XDRA command.
The XDR(B) sentence may be enabled via the $PAMTC,EN,XDRB command.
The wind chill temperature is the perceived temperature on a person’s face at
the current wind speed. The calculation assumes that the wind speed measured by
the sensor is the same as the wind speed at the face of an observer. The “relative”
wind chill uses the measured apparent wind speed for this calculation, and the
“theoretical” wind chill uses the calculated true wind speed. The wind chill
temperature is only defined when the air temperature is below 50°F (10°C) and
the wind speed is above 3 mph.
The heat index is the apparent temperature felt by a person's skin when exposed
to air with a high moisture content. Dry air allows evaporative cooling of the
skin's surface. The higher the humidity, the less the skin can cool itself with
evaporative cooling. The heat index is only defined when air temperature is
above 80°F (27°C) and relative humidity is above 40%.
The barometric station pressure is the raw, uncorrected barometric pressure
reading. This is provided here in the XDRA sentence, and is distinct from the
altimeter setting, which is the barometric pressure corrected for altitude, provided
in the MDA sentence.
The reported pitch and roll values are adjusted by the azimuth, pitch, and roll
offsets established with the $PAMTC,ATTOFF command.
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NMEA 0183 TRANSMITTED SENTENCE
$GPZDA
Summary
NMEA 0183 standard Time and Date.
Syntax
Fields
$GPZDA,<1>,<2>,<3>,<4>,<5>,<6>*hh<CR><LF>
<1>
UTC time of day, in the form hhmmss
<2>
UTC day, 01 to 31
<3>
UTC month, 01 to 12
<4>
UTC year (four digits, e.g. 2006)
<5>
Local time zone hours, 00 to +/-13 hrs
<6>
Local time zone minutes, 00 to +59
Default State
Enabled. Transmitted once per second.
Notes
This sentence may be enabled or disabled via the $PAMTC,EN,ZDA command.
Local time zone is the magnitude of hours plus the magnitude of minutes added,
with the sign of local zone hours, to local time to obtain UTC. Local zone is
generally negative for East longitudes with local exceptions near the International
Date Line.
Examples:
At Chatham Is. (New Zealand) at 1230 (noon) local time on June 10,
1995:
$GPZDA,234500,09,06,1995,-12,45*6C<CR><LF>
In the Cook Islands at 1500 local time on June 10, 1995:
$GPZDA,013000,11,06,1995,10,30*4A<CR><LF>
In the LB150, the local time zone is not changeable via the NMEA 0183 interface.
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2.2.
Received NMEA 0183 Sentences and Commands
The LB150 WeatherStation has an NMEA 0183-compliant input channel that is capable
of receiving standard NMEA sentences as well as proprietary commands for
initialization, calibration, or to modify the behavior of the unit.
All received sentences and commands can include or omit the NMEA checksum. If a
checksum is included, the sentence will be checked against its checksum, and the
sentence will be accepted only if there is a checksum match. If the NMEA checksum is
excluded, it is required that the preceding asterisk (*) also be excluded. If no checksum
is provided, the LB150 WeatherStation will accept the sentence without error checking.
It is recommended that all sentences and commands provided to the WeatherStation
include a checksum to help ensure integrity of the transmitted data.
The sentences recognized by the LB150 WeatherStation on the serial input channel are
summarized in Table 2 on the next page.
Note that the prefix “$--” appearing in the descriptions for several of the listed
sentences should be replaced by a “$” followed by the two-character talker ID of the
transmitting device.
Each of the sentences in Table 2 is described in detail on the subsequent pages.
2.2.1. Precedence of Data
In a given installation, certain data items might be available from more than one source.
In this circumstance, the following precedence rules apply. The calculation of true wind,
in particular, depends on these precedence rules.
Heading and Deviation:
$--HDT supersedes $--HDG and the internal compass.
$--HDG supersedes the internal compass
$--VHW (Note: if heading is supplied in this received sentence, it is ignored.)
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Table 2: NMEA 0183 Received Sentences and Commands
Sentence or
Command
Description
$--HDG
Standard NMEA Heading, Deviation, and Variation
$--HDT
Standard NMEA Heading, True
$--VHW
Standard NMEA Water Speed and Heading (for water
speed)
$PAMTC,ALT
Program the LB150 WeatherStation with altitude
settings
$PAMTC,ATTOFF
Program the LB150 WeatherStation with angular
attitude offsets: azimuth, pitch, and roll
$PAMTC,BAUD
Change the baud rate from the nominal 4800 baud to
38400 baud
$PAMTC,DATUM
Define the local datum to which GPS position locations
are referenced
$PAMTC,EN
Enable/disable transmission of specific sentences, and
change their rate of transmission
$PAMTC,ERST
Reset the user portion of nonvolatile EEPROM to
factory defaults
$PAMTC,HEATER
Control the WeatherStation internal heater.
$PAMTC,OPTION
Enable/disable certain WeatherStation features
$PAMTC,POST
Query Power On Self Test results
$PAMTC,QPS
Query part number and serial number strings
$PAMTC,QV
Query WeatherStation hardware and firmware versions
$PAMTC,RESET
Reset the LB150 WeatherStation
$PAMTC,SIM
Enable/disable Simulate Mode.
$PAMTX
Pause or resume all automatic transmission of
messages
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_NMEA 0183 RECEIVED SENTENCE_
$--HDG
Summary
NMEA 0183 standard Heading, Deviation and Variation.
Syntax
Fields
Notes
$--HDG,<1>,<2>,<3>,<4>,<5>*hh<CR><LF>
<1>
Magnetic sensor heading, degrees.
<2>
Magnetic deviation, degrees east or west.
<3>
E if field <2> is degrees East
W if field <2> is degrees West
<4>
Magnetic variation, degrees east or west.
<5>
E if field <4> is degrees East
W if field <4> is degrees West
See section 2.2.1. for precedence rules regarding data received via this sentence.
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_NMEA 0183 RECEIVED SENTENCE_
$--HDT
Summary
NMEA 0183 standard Heading, True.
Syntax
Fields
Notes
$--HDT,<1>,<2>*hh<CR><LF>
<1>
Magnetic sensor heading, degrees.
<2>
T = True.
See section 2.2.1. for precedence rules regarding data received via this sentence.
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_NMEA 0183 RECEIVED SENTENCE_
$--VHW
Summary
NMEA 0183 standard Water Speed and Heading.
Syntax
Fields
Notes
$--VHW,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>*hh<CR><LF>
<1>
Compass Heading, degrees True
<2>
T = true
<3>
Compass Heading, degrees Magnetic
<4>
M = magnetic
<5>
Water speed, knots
<6>
N = knots
<7>
Water speed, km/h
<8>
K = km/h
This sentence is used to obtain water speed from an Airmar® Smart™ speed
sensor. The water speed data is used to calculate true wind relative to the water.
The compass heading fields in this sentence are ignored by the LB150
WeatherStation.
See section 2.2.1. for precedence rules regarding data received via this sentence.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC
Summary
Prefix for recognized proprietary commands.
Syntax
Fields
$PAMTC,<1>…*hh<CR><LF>
<1>
Command mnemonic. This may be any of the following:
ALT
ATTOFF
BAUD
DATUM
EN
ERST
HEATER
OPTION
POST
QPS
QV
RESET
SIM
The number and meaning of any subsequent fields is dependent on the command
mnemonic. Each of the command mnemonics defines a separate proprietary
command (or set of commands) recognized by the LB150 WeatherStation. These
commands are each described in their own section on the following pages.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,ALT
Summary
Settings related to the altitude of the LB150.
Syntax
One of the following forms:
$PAMTC,ALT,SET,<2>,<3>,<4>*hh<CR><LF>
$PAMTC,ALT,Q*hh<CR><LF>
Fields
<2>
Fixed altitude, -999.9 meters to +40,000.0 meters, to the nearest 0.1
meter.
Default value = 0 meters
<3>
0 = Do not use fixed altitude for GPS 2D mode
1 = Use fixed altitude for GPS 2D mode
Default value = 0
<4>
0 = Do not use altitude for barometric pressure altimeter setting
($WIMDA, fields 1 and 3)
1 = Barometric pressure altimeter setting uses fixed altitude (field
<2>).
2 = Barometric pressure altimeter setting uses GPS altitude when
GPS has a 3D fix, or fixed altitude (field <2>) when GPS does
not have a 3D fix.
Default value = 2.
Notes
The $PAMTC,ALT,SET,<2>,<3>,<4> command is used to program the LB150
WeatherStation with a fixed altitude setting to be used in calculating a more
accurate GPS position when the GPS is operating in 2D mode, and in calculating
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the barometric pressure altimeter setting provided in fields 1 and 3 of the
transmitted $WIMDA sentence.
Fields <3> and<4> of the $PAMTC,ALT,SET command define how to use the
altitude setting provided in field <2>.
All of the parameters of the $PAMTC,ALT,SET command are stored in
nonvolatile EEPROM memory within the LB150, and so remain programmed
even after cycling power. If any of the fields <2>, <3>, or <4> are null fields, the
corresponding stored value will remain unchanged.
The $PAMTC,ALT,Q command is used to query the values of the parameters
currently programmed into the LB150. The unit will reply with
$PAMTR,ALT,a,b,c
where a, b, and c correspond to fields <2>, <3>, and <4>, respectively, in the
$PAMTC,ALT,SET command.
See also:
NMEA 0183 received proprietary sentence $PAMTC,OPTION, option 2.
NMEA 0183 transmitted sentence $YXXDR (barometric pressure).
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$PAMTC,ATTOFF
_NMEA 0183 RECEIVED SENTENCE_
Summary
A set of proprietary commands to set and query the angular attitude offsets for the
LB150 WeatherStation when mounted on a vehicle, and not necessary for
stationary instruments.
Syntax
One of the following forms:
$PAMTC,ATTOFF,SET,<3>,<4>,<5>*hh<CR><LF>
$PAMTC,ATTOFF,Q*hh<CR><LF>
Fields
Notes
<3>
Signed azimuth offset (yaw offset), degrees, to the nearest tenth
of a degree. The value must be between -180.0 and +180.0
degrees. Negative values indicate the forward mark on the
sensor housing is oriented toward the right side of the vehicle;
positive values toward the left side.
<4>
Signed pitch offset, degrees, to the nearest tenth of a degree.
The value must be between -45.0 and +45.0 degrees. Positive
values indicate the sensor is tilted forward toward the front of
the vehicle; negative values indicate the sensor is tilted toward
the back of the vehicle.
<5>
Signed roll offset, degrees, to the nearest tenth of a degree. The
value must be between -45.0 and +45.0 degrees. Positive
values indicate the sensor is tilted toward the left side; negative
values toward the right side.
Note that in the NMEA 0183 command, the arguments are in degrees. The values
stored in the LB150 are in radians. Therefore, when using the
$PAMTC,ATTOFF command, there may be a slight rounding error causing the
values read back from the LB150 to be different than the commanded values by
one least significant digit.
The $PAMTC,ATTOFF,SET,<3>,<4>,<5> command is used to program the
LB150 WeatherStation with the attitude offset angles when the sensor is not
oriented parallel to the centerline, and perpendicular to the wheel base of the
vehicle. The programmed values are stored in nonvolatile EEPROM memory
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within the WeatherStation, and so remain programmed even after cycling power.
If any of the fields <3>, <4>, or <5> are null fields, the corresponding stored
value will remain unchanged.
The $PAMTC,ATTOFF,Q command is used to query the values of the attitude
offset angles currently programmed into the WeatherStation. The unit will reply
with
$PAMTR,ATTOFF,a,b,c
where a is the current signed azimuth offset value, b is the current signed pitch
offset value, and c is the current signed roll offset value. All values are reported
to the nearest tenth of a degree.
The factory default value for all three parameters is 0.0 degrees.
The azimuth offset angle is used to adjust the apparent wind angle relative to the
front of the vehicle, and the vehicle’s heading when using the internal compass.
These values are further used in calculating the true wind speed and angle.
The azimuth offset angle, along with the pitch and roll offset angles are also used
to adjust the reported pitch and roll values in the transmitted $WIXDR sentence.
A properly set azimuth offset angle will allow the unit to accurately report pitch
and roll of the vehicle, even though the orientation mark on the sensor housing
may not be facing precisely toward the front of the vehicle. The recommended
procedure to set these offsets is as follows:
1. If the unit is mounted on a vehicle, this procedure should be performed with
the vehicle at rest on level ground.
2. First, zero out all offsets by sending the command
$PAMTC,ATTOFF,SET,0,0,0.
3. Determine the desired azimuth offset angle, and program this into the sensor
using the command $PAMTC,ATTOFF,SET,a where a is the azimuth offset
of the sensor relative to the front of the vehicle, in degrees. The pitch and roll
offset fields should be omitted for this step (or set to zeroes).
4. Allow the vehicle to come to rest in a "level" state, and then read the values of
pitch and roll that are reported by the XDR sentence.
5. Program the negated versions of these measured pitch and roll values back
into the unit with the $PAMTC,ATTOFF,SET,,b,c sentence. For example, if
the XDR sentence reports an average pitch angle of 6.2 degrees, and an
average roll angle of -4.3 degrees, then you would send the sentence
$PAMTC,ATTOFF,SET,,-6.2,4.3 to the WeatherStation. Note that the
azimuth offset field in this sentence is a null field, indicating we are not
changing its value at this time.
6. At this point the transmitted XDR sentences should be producing values that
are centered around 0.0 degrees for both pitch and roll.
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7. The programmed attitude offset values may be checked at any time by sending
the command $PAMTC,ATTOFF,Q to the unit; it will reply with
$PAMTR,ATTOFF,a,b,c.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,BAUD
Summary
Change the baud rate for both the transmitting and receiving NMEA 0183
channels.
Syntax
One of the following forms:
$PAMTC,BAUD,4800*hh<CR><LF>
$PAMTC,BAUD,38400*hh<CR><LF>
Notes
The $PAMTC,BAUD command may be used to increase the baud rate from the
standard 4800 baud to 38400 baud. This will provide an eightfold increase in the
bandwidth of the NMEA 0183 interface, allowing more data to be transmitted in a
given period of time.
On power up, the NMEA input and output interfaces always default to 4800 baud.
It is recommended to employ the following sequence when changing the baud rate
for the WeatherStation from 4800 baud to 38400 baud. The following assumes
there is a single host device communicating with the WeatherStation:
1. Send the $PAMTX command to the WeatherStation (at 4800 baud) to
temporarily disable transmission of periodic sentences.
2. Send the $PAMTC,BAUD,38400 command (at 4800 baud) to instruct the
WeatherStation to change its baud rate to 38400. The unit will finish
transmitting any periodic sentences in progress at 4800 baud, and will then
change its interface to use 38400 baud.
3. Delay a short interval within the host to allow reception of any remaining
queued sentences from the WeatherStation at 4800 baud.
4. Change the baud rate on the host's serial port to 38400 baud.
5. Send the $PAMTX,1 command to the WeatherStation (at 38400 baud) to
resume transmission of periodic sentences.
6. All subsequent communication with the WeatherStation will be at 38400
baud, until the unit is powered down or reset, or the
$PAMTC,BAUD,4800 command is sent to the unit.
Note that a baud rate of 38400 does not comply with the NMEA 0183 standard.
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$PAMTC,COMP
_NMEA 0183 RECEIVED SENTENCE_
Summary
User calibration commands for the internal compass sensor. This can not be used
for stationary instruments.
Syntax
One of the following forms:
$PAMTC,COMP,GO*hh<CR><LF>
$PAMTC,COMP,RESETALL*hh<CR><LF>
$PAMTC,COMP,RESETCAL*hh<CR><LF>
$PAMTC,COMP,RESETDAMP*hh<CR><LF>
$PAMTC,COMP,SET,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
$PAMTC,COMP,Q*hh<CR><LF>
$PAMTC,COMP,X*hh<CR><LF>
$PAMTC,COMP,VERIFY*hh<CR><LF>
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$PAMTC,COMP,GO
Summary
Initiate a user calibration sequence for the internal compass sensor.
Syntax
$PAMTC,COMP,GO*hh<CR><LF>
The user calibration sequence for the LB150 is as follows:
1. The weather station is installed on the vehicle. The unit under test is powered
up.
2. The $PAMTC,COMP,GO*hh<CR><LF> command is sent to the weather
station’s NMEA 0183 input channel to initiate user calibration mode.
3. During the user calibration process, the vehicle is rotated slowly (driven in a
circle) and the sensor calculates the resulting coefficients. Once the weather
station has determined that enough data has been collected for the purpose of
calculating the coefficients, it transmits the following sentence:
$PAMTR,COMP,XXXX,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>. Where
XXXX is “PASS” or “FAIL”.
4. If PASS was transmitted, then the offsets that are now in use and saved in
EEPROM are the newly calculated ones.
Reply
The weather station will reply immediately with:
$PAMTR,COMP,INPROCESS,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
Where fields <1> through <9> contain the data from the weather station’s
nonvolatile EEPROM, as defined in the “Q”, Query Command.
Upon successful completion the weather station will reply with:
$PAMTR,COMP,PASS,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
Or, upon failure it will reply with:
$PAMTR,COMP,FAILx,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
Where x indicates the type of failure, 1 = Timeout, 2 = Tilt Error, or 3 = Other
Error.
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$PAMTC,COMP,RESETALL
Summary
Reset the user calibration coefficients and damping control to the default values.
Syntax
Reply
$PAMTC,COMP,RESETALL*hh<CR><LF>
The weather station will reset the user calibration coefficients and damping
control (fields 1-9) and reply with:
$PAMTR,COMP,RESETALL,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
where fields <1> through <9> contain the data from the weather station’s
nonvolatile EEPROM, as defined in the “Q”, Query Command.
$PAMTC,COMP,RESETCAL
Summary
Reset the user calibration coefficients to the default values.
Syntax
Reply
$PAMTC,COMP,RESETCAL*hh<CR><LF>
The weather station will reset the user calibration coefficients (fields 1 – 6) and
reply with:
$PAMTR,COMP,RESETCAL,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
where fields <1> through <9> contain the data from the weather station’s
nonvolatile EEPROM, as defined in the “Q”, Query Command.
$PAMTC,COMP,RESETDAMP
Summary
Reset the user damping control to the default values.
Syntax
Reply
$PAMTC,COMP,RESETDAMP*hh<CR><LF>
The weather station will reset the user damping control (fields 7-9) and reply
with:
$PAMTR,COMP,RESETDAMP,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
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where fields <1> through <9> contain the data from the weather station’s
nonvolatile EEPROM, as defined in the “Q”, Query Command.
$PAMTC,COMP,SET
Summary
Set one or more user compass calibration coefficients.
Syntax
$PAMTC,COMP,SET,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh
<CR><LF>
where fields <1> through <9> contain the data to be set into the weather station’s
nonvolatile EEPROM corresponding to the fields as follows.
All fields are 16-bit signed fixed point decimal integers.
<1>
X axis Gain value, hundredths used as multiplier.
Notes
<2>
Y axis Gain value, hundredths used as multiplier.
<3>
Z axis Gain value, hundredths used as multiplier.
<4>
X axis linear offset, hundredths of micro-Teslas.
<5>
Y axis linear offset, hundredths of micro-Teslas.
<6>
Z axis linear offset, hundredths of micro-Teslas.
<7>
X axis angular offset, tenths of degrees.
<8>
Pitch and Roll Damping, twentieths of a second.
<9>
Compass/RateGyro Damping, twentieths of a second.
Currently only Linear Offsets (X and Y) and Damping values are supported.
Valid ranges for data:
Gain: 50 to 500
Linear Offset: -32000 to +32000
X-Angular Offset: 0 to 3600
Pitch and Roll Damping: 0 to 200
Compass/RateGyro Damping: 0 to 2400
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$PAMTC,COMP,Q
Summary
Query the weather station for the stored user compass calibration coefficients.
Syntax
Reply
$PAMTC,COMP,Q*hh<CR><LF>
The weather station will reply with:
$PAMTR,COMP,Q,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
where fields <1> through <9> contain the data from the weather station’s
nonvolatile EEPROM corresponding to the fields as follows.
All fields are 16-bit signed fixed point decimal integers.
Notes
<1>
X axis Gain value, hundredths used as multiplier.
<2>
Y axis Gain value, hundredths used as multiplier.
<3>
Z axis Gain value, hundredths used as multiplier.
<4>
X axis linear offset, hundredths of micro-Teslas.
<5>
Y axis linear offset, hundredths of micro-Teslas.
<6>
Z axis linear offset, hundredths of micro-Teslas.
<7>
X axis angular offset, tenths of degrees.
<8>
Pitch and Roll Damping, twentieths of a second.
<9>
Compass/RateGyro Damping, twentieths of a second.
Currently only Linear Offsets (X and Y) and Damping values are supported.
If in user calibration mode, the “Q” will be replaced by “INPROGRESS”.
If a user calibration pass has been completed, the “Q” will be replaced by
“PASS” or “FAIL”.
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$PAMTC,COMP,X
Summary
Terminate the user compass calibration mode.
Syntax
Reply
Notes
$PAMTC,COMP,X*hh<CR><LF>
$PAMTR,COMP,X,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
Upon receiving $PAMTC,COMP,X user calibration mode will be terminated, if it
had been previously entered by a $PAMTC,COMP,GO. The reply will always be
issued.
If not in user calibration mode, the “X” will be replaced by “Q”.
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$PAMTC,COMP,VERIFY
Summary
Verify the user compass calibration mode.
Syntax
$PAMTC,COMP,VERIFY*hh<CR><LF>
The verify user calibration sequence for the LB150 is as follows:
1. The weather station is installed on the vehicle. The unit under test is powered
up. User calibration has been completed successfully.
2. The $PAMTC,COMP,VERIFY*hh<CR><LF> command is sent to the
weather station’s NMEA 0183 input channel to initiate user calibration mode.
3. During the verify user calibration process, the vehicle is rotated slowly (driven
in a circle) and the sensor calculates the resulting score. Once the weather
station has determined that enough data has been collected, it transmits the
following sentence: $PAMTR,COMP,SCORE,XXX*hh<CR><LF>
Reply
The weather station will reply immediately with:
$PAMTR,COMP,INPROGRESS,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
Where fields <1> through <9> contain the data from the weather station’s
nonvolatile EEPROM, as defined in the “Q”, Query Command.
Upon successful completion the weather station will reply with:
$PAMTR,COMP,SCORE,XXX*hh<CR><LF>
Where XXX is a score from 0 – 255, meaning TBD.
Or, upon failure it will reply with:
$PAMTR,COMP,FAILx,
<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>
Where x indicates the type of failure, 1 = Timeout, 2 = Tilt Error, or 3 = Other
Error.
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$PAMTC,DATUM
_NMEA 0183 RECEIVED SENTENCE_
Summary
Define the local datum to which GPS position locations are referenced.
Syntax
One of the following forms:
$PAMTC,DATUM,SET,<3>,<4>*hh<CR><LF>
$PAMTC,DATUM,Q*hh<CR><LF>
Fields
Notes
<3>
Three character alphabetical code for local datum:
W84 (WGS84)
W72 (WGS72)
S85 (SGS85)
P90 (PE90)
or IHO datum code from the International Hydrographic
Organization Publication S-60 Appendices B and C.
<4>
One character subdivision datum code when available, as defined in
IHO Publication S-60 Appendices B and C.
The $PAMTC,DATUM,SET,<3>,<4> command is used to establish the local
datum used by the GPS receiver for calculating position. These values are stored
in EEPROM memory within the unit. The default value for field <3> is W84
(WGS84). The default value for field <4> is a null field (no subdivision datum
code).
Unlike other NMEA 0183 proprietary commands, if in the command
$PAMTC,DATUM,SET,<3>,<4> field <4> is a null field, the value will be
actually set to null (no subdivision datum code).
The $PAMTC,DATUM,Q command may be used to determine the current datum
setting within the unit. Upon receiving this command, the unit will reply with
$PAMTR,DATUM,<3>,<4>, where fields <3> and <4> are as described above.
The value established by this command will be used by the transmitted $GPDTM
sentence.
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KGS, OHI-A, OHI-B, OHI-C, OHI-D, OHI-M, SIR, P90, and S85 are not
currently supported by the GPS Engine used in the LB150, and therefore are not
available for use as Local Datum.
Important Note: Chart transformations based on IHO S60 parameters may result
in significant positional errors when applied to chart data.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,EN
Summary
Enable or disable the periodic transmission of individual standard NMEA 0183
sentences, and specify their rate of transmission.
Syntax
One of the following forms:
$PAMTC,EN,<2>,<3>,<4>*hh<CR><LF>
$PAMTC,EN,S*hh<CR><LF>
$PAMTC,EN,L*hh<CR><LF>
$PAMTC,EN,LD*hh<CR><LF>
$PAMTC,EN,Q*hh<CR><LF>
Fields
<2>
The identifier ALL, or one of the following sentence ID’s:
DTM, GGA, GLL, GSA, GSV, HDG, HDT, MDA,
MWD, MWVR, MWVT, RMC, ROT, VTG, VWR, VWT,
XDRA, XDRB, ZDA
<3>
If field <2> is the ALL identifier, then
0 = disable transmission of all sentences
1 = enable transmission of all sentences.
Otherwise,
0 = disable transmission of the specified sentence
1 = enable transmission of the specified sentence
<4>
The amount of time between successive transmissions of the specified
sentence, in tenths of a second. For example, if field <4> contains the
value 5, this specifies an interval of 0.5 seconds between successive
transmissions of the specified sentence.
If field <2> is the ALL identifier, then field <4> specifies the
transmission interval for all sentences.
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Notes
The factory default settings are as follows:
Sentence ID Enabled by default?
DTM
–
GGA
GLL
–
GSA
–
GSV
–
HDG
–
HDT
MDA
MWD
–
MWV (R)
MWV (T)
–
RMC
–
VTG
VWR
–
VWT
–
XDR (A)
XDR (B)
ZDA
Default Transmission Interval
10
10
10
10
10
5
5
10
10
5
10
10
10
10
10
10
10
10
Note that the MWV sentence appears in two forms: relative (R) and theoretical (T).
These two forms are enabled separately.
Also note that the XDR sentence appears in two forms: A and B. These two forms are
also enabled separately.
If either of fields <3> or <4> is a null field, then that field will remain unchanged from its
previous value.
The selections as to which sentences are enabled for transmission, and the rate at which
each sentence is transmitted, are stored in nonvolatile EEPROM memory within the
LB150 WeatherStation unit. On power up, these settings are copied from EEPROM into
a working copy in RAM memory. It is the working copy in RAM that determines the
behavior of the WeatherStation, with regard to the transmission of sentences.
Any changes to these settings using the $PAMTC,EN,<2>,<3>,<4> command only affect
the working copy in RAM. When power is lost, the changes to the working copy in
RAM will be lost.
The $PAMTC,EN,S command causes the contents of the current working copy in RAM
to be saved to EEPROM. The saved settings will then be restored to RAM each time
power is applied to the unit.
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The $PAMTC,EN,L command allows the settings to be reloaded from EEPROM to
RAM without cycling power to the unit. This can be used to discard any changes made
to the working copy in RAM, and restore the saved settings as though the unit had been
turned off and then back on again.
The $PAMTC,EN,LD command loads the factory default settings from ROM memory
into RAM memory.
Note that the $PAMTC,ERST command (see separate description) differs from the
$PAMTC,EN,LD command in that $PAMTC,ERST will initialize all of user EEPROM
memory to its factory default settings. This includes settings unrelated to the selection of
transmitted sentences.
The above paragraphs are summarized in the below figure.
Working Copy
(RAM)
N
,E
TC
D
,L
Saved Copy
(EEPROM)
AM
$P
S
N,
L
,E
C
N,
T
,E
M
C
A
T
$P
AM
$P
$PAMTC,ERST
Factory Defaults
(ROM)
The $PAMTC,EN,Q command provides a query function to allow reading the current
settings from the working copy in RAM. The reply to the $PAMTC,EN,Q command is a
series of sentences with the following format:
$PAMTR,EN,<1>,<2>,<3>,<4>,<5>*hh<CR><LF>
where
<1> = Total number of $PAMTR,EN sentences in the reply
<2> = Sentence number
<3> = Sentence ID (GGA, GLL, GSA, GSV, HDG, MDA, MWD, MWVR,
MWVT, RMC, VTG, VWR, VWT, or XDR)
<4> = 0 or 1 (0=disabled, 1=enabled)
<5> = Transmission interval (tenths of a second)
For example, a unit programmed with only the factory default settings would provide the
following as a reply to the $PAMTC,EN,Q command:
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$PAMTR,EN,19,1,DTM,1,10*17
$PAMTR,EN,19,2,GGA,1,10*17
$PAMTR,EN,19,3,GLL,0,10*13
$PAMTR,EN,19,4,GSA,0,10*00
$PAMTR,EN,19,5,GSV,0,10*10
$PAMTR,EN,19,6,HDG,0,5*2C
$PAMTR,EN,19,7,HDT,0,5*22
$PAMTR,EN,19,8,MDA,1,10*19
$PAMTR,EN,19,9,MWD,1,10*0E
$PAMTR,EN,19,10,MWVR,1,5*75
$PAMTR,EN,19,11,MWVT,1,10*46
$PAMTR,EN,19,12,RMC,0,10*3B
$PAMTR,EN,19,14,VTG,1,10*21
$PAMTR,EN,19,15,VWR,0,10*37
$PAMTR,EN,19,16,VWT,1,10*37
$PAMTR,EN,19,17,XDRA,0,10*6D
$PAMTR,EN,19,18,XDRB,0,5*59
$PAMTR,EN,19,19,ZDA,1,10*3E
Keep in mind when enabling sentences that the overall bandwidth of the interface should
not be exceeded. At 4800 baud, only 480 characters can be transmitted in a one second
period of time. If every one of the above sentences were enabled for transmission, their
total number of characters could exceed 800. It is possible to use the $PAMTC,EN
command to overspecify the amount of data transmitted, beyond the bandwidth capacity
of the NMEA output channel. See section 2.1. for further information regarding bus
bandwidth.
Examples
Example 1:
To disable all sentences for transmission, except transmit compass heading 5
times per second, and save the settings in EEPROM, send the following sequence
of commands to the unit:
$PAMTC,EN,ALL,0
$PAMTC,EN,HDG,1,2
$PAMTC,EN,S
Example 2:
To reload the factory defaults for the $PAMTC,EN settings into EEPROM
without affecting other EEPROM settings (such as attitude offsets set with the
$PAMTC,ATTOFF command), send the following sequence of commands to the
unit:
$PAMTC,EN,LD
$PAMTC,EN,S
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Example 3:
To enable transmission of the XDR (A) sentence and set it to transmit at the slow
rate of once every 10 seconds for the current session only, send the following
command to the unit:
$PAMTC,EN,XDRA,1,100
Example 4:
To disable transmission of the MWV(T) sentence permanently:
$PAMTC,EN,MWVT,0
$PAMTC,EN,S
Example 5:
To enable transmission of all of the GPS-related sentences, and disable all others,
for the current session only:
$PAMTC,EN,ALL,0
$PAMTC,EN,DTM,1
$PAMTC,EN,GGA,1
$PAMTC,EN,GLL,1
$PAMTC,EN,GSA,1
$PAMTC,EN,GSV,1
$PAMTC,EN,RMC,1
$PAMTC,EN,VTG,1
$PAMTC,EN,ZDA,1
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,ERST
Summary
Reset the user portion of nonvolatile EEPROM to its factory default state.
Syntax
Notes
$PAMTC,ERST*hh<CR><LF>
The following data items are saved in nonvolatile EEPROM within the LB150
WeatherStation. For each item, the default value, and the command used to
change the value is shown.
Item
Default value
Changed via command
Azimuth offset
0.0°
$PAMTC,ATTOFF
Pitch offset
0.0°
$PAMTC,ATTOFF
Roll offset
0.0°
$PAMTC,ATTOFF
List of sentences
enabled for transmission
See the description for the
$PAMTC,EN command
$PAMTC,EN
Rates of transmission of
sentences
See the description for the
$PAMTC,EN command
$PAMTC,EN
Disabled
$PAMTC,OPTION
GPS fix 2D, 3D, or Auto
Auto
$PAMTC,OPTION
Altitude settings
0,1,2
$PAMTC,ALT
Allow COG to be used
instead of internal
compass heading in true
wind calculations
Other items related to factory calibration of the sensor are also saved in
EEPROM, but these items are not affected by the $PAMTC,ERST command.
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$PAMTC,HEATER
_NMEA 0183 RECEIVED SENTENCE_
Summary
Control the internal heater within the weather station.
Syntax
Notes
One of the following forms:
$PAMTC,HEATER,0*hh<CR><LF>
Turn heater off (default state).
$PAMTC,HEATER,A*hh<CR><LF>
Control heater automatically.
$PAMTC,HEATER,Q*hh<CR><LF>
Query heater status, and start
reporting subsequent changes in
status
$PAMTC,HEATER,X*hh<CR><LF>
Stop reporting heater status change
The heater may be used in the weather station to prevent the formation of dew or
ice on the aluminum plate in the wind channel. If the heater control is set to "A"
(automatic control), then the weather station will automatically cycle the heater on
and off over time to keep the plate temperature within appropriate limits based on
the air temperature (and dew point temperature, if product has humidity sensor,
PBxxx products do not, LBxxx products do).
If a $PAMTC,HEATER,Q (Query) command is received, then every time the
heater status changes, the sensor will transmit the following message:
$PAMTR,HEATER,<1>,<2>,<3>*hh<CR><LF>
where
<1> = Heater mode (M = manual, A = automatic)
<2> = Heater state (0 = heater Off, 1 = heater On)
<2> = Heater control (V = Valid, if Factory enabled, else NULL)
Heater status change reporting may be disabled with the $PAMTC,HEATER,X
command.
Note that when the heater is on, the air temperature sensor within the unit will be
heated by the heater and will not provide an accurate indication of outside
ambient air temperature.
This is a factory enabled option that is not present by default.
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$PAMTC,OPTION
_NMEA 0183 RECEIVED SENTENCE_
Summary
Enable or disable certain WeatherStation features, or query their state.
Syntax
One of the following forms:
$PAMTC,OPTION,SET,<3>,<4>*hh<CR><LF>
$PAMTC,OPTION,Q,<3>*hh<CR><LF>
Fields
Option 1:
<3>
1 = Allow COG to be used instead of internal compass heading in true
wind calculations
<4>
1 = Feature enabled
0 = Feature disabled (default)
Option 2:
<3>
2 = Set GPS fix mode
<4>
1 = 2D fix only
2 = 3D fix only
3 = Automatic selection of 2D or 3D mode (default)
Option 3:
<3>
3 = Set WAAS mode
<4>
0 = WAAS Disabled
1 = WAAS Enabled, but report fixes as GPS, Autonomous
2 = WAAS Enabled, report fixes as Differential
Option 4:
<3>
4 = Set WAAS Satellite
<4>
0 = Auto Mode (default)
120-138 = WAAS Satellite ID
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Option 5:
Notes
<3>
5 = Enable Type 0 Messages
<4>
0 = Ignore Type 0 messages for 60 seconds
1-39 = Enable Type 0 messages as data
255 = Ignore Type 0 messages (default)
Option 1:
If the local magnetic inclination (dip) is severe, this can produce errors in the
compass heading when the vehicle is not level. Since the compass heading is
used in the calculations for true wind, this can also result in errors in the reported
true wind speed and direction. (Apparent wind is not affected.) This option is not
applicable to stationary instruments.
The WeatherStation can be instructed to use Course Over Ground (COG)
provided by the internal GPS in place of the internal compass heading in the
calculations for true wind. The command to enable this feature is
$PAMTC,OPTION,SET,1,1. If this feature is enabled, then the COG will be used
instead of internal compass heading for calculation of true wind only if the GPS
has achieved a fix, and if the Speed Over Ground (SOG) is greater than 3 knots.
If there is no GPS fix, or if the SOG is 3 knots or less, then the internal compass
heading will be used.
Do be aware when using this feature that Heading and COG are not the same.
Heading refers to the direction the front of the vehicle is pointing. COG refers to
the direction the vehicle is traveling. While in an vehicle these values are likely
to be nearly identical, in a boat they can differ because of the effects of wind and
current on the vessel. The rationale for using COG instead of heading in the
calculations for true wind is that the difference between COG and actual heading
might be less than the error in the reported compass heading due to dip.
The setting is saved in nonvolatile EEPROM within the WeatherStation.
To disable this feature, use the command $PAMTC,OPTION,SET,1,0. When
disabled, the COG will not be used in place of internal compass heading under
any circumstances.
The WeatherStation may be queried to determine the state of this feature. If the
command $PAMTC,OPTION,Q,1 is received, the unit will transmit the reply
$PAMTR,OPTION,1,0 if the feature is disabled, or $PAMTR,OPTION,1,1 if
enabled.
Option 2:
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The GPS receiver in the LB150 can calculate a position fix when it has achieved a
lock on at least three GPS satellites. If it has achieved a lock on four or more
satellites, the unit may be able to calculate a 3D position fix, meaning it can
determine latitude, longitude, and altitude. But if it has achieved a lock on only
three satellites, it may only be able to calculate a 2D position fix, meaning it can
determine latitude and longitude, but not altitude.
By default, the unit will automatically calculate a 3D position fix if it is able to,
but will fall back to 2D position fixing if there are not enough satellites being
tracked.
It is possible to restrict the operation of the GPS to only allow 3D position fixes
by sending the unit the command $PAMTC,OPTION,SET,2,2. If this is done,
then the unit will not calculate a position fix until it has achieved a lock on at least
four satellites.
Note that sometimes the GPS may be tracking at least four satellites, but is still
unable to calculate a position fix. This is because the positions of the satellites in
the sky must be satisfactory in order to achieve good geometry in the fix
calculation, as determined by the HDOP, VDOP, and PDOP values.
It is also possible to restrict the operation of the GPS to only allow 2D position
fixes by sending the unit the command $PAMTC,OPTION,SET,2,1.
To re-enable the automatic selection of 2D versus 3D fix calculations, send the
unit the command $PAMTC,OPTION,SET,2,3.
This setting is stored in EEPROM within the unit, and retrieved on power up.
The current setting may be queried by issuing the $PAMTC,OPTION,Q,2
command. The unit will respond with the sentence $PAMTR,OPTION,Q,2,<4>,
where the value of <4> is 1, 2, or 3, corresponding to 2D, 3D, or Automatic
mode, respectively.
When calculating a 2D position fix, the latitude/longitude values may have a
relatively large error if the altitude of the GPS receiver is not set appropriately.
This can be corrected by programming a fixed altitude offset into the unit. See
the $PAMTC,ALT command on page 35.
Note that sometimes the GPS may be tracking at least four satellites, but is still
unable to calculate a position fix. This is because the positions of the satellites in
the sky must be satisfactory in order to achieve good geometry in the fix
calculation, as determined by the HDOP, VDOP, and PDOP values.
Option 3:
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The Wide Area Augmentation System (WAAS) uses a system of land based
reference stations and geostationary satellites to augment the Global Positioning
System (GPS) in order to provide additional accuracy, integrity, and availability.
Several GPS Sentences are able to differentiate between WAAS (Differential)
fixes and those fixes that do not use WAAS corrections.
The available WAAS modes are:
0 – Disable WAAS
1 – Enable WAAS, but report WAAS fixes as GPS (Autonomous, nondifferential). This is provided for backward compatibility for systems that
might not recognize WAAS (Differential) fixes.
2 – Enable WAAS, and report WAAS fixes as Differential.
The default mode is 2.
This setting is stored in EEPROM within the unit, and retrieved on power up.
Option 4:
This option can be used to direct the GPS to use a specific WAAS satellite. This
value is NOT stored in EEPROM.
Option 5:
This option can be used to direct the GPS how to handle type 0 messages. This
value is NOT stored in EEPROM.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,POST
Summary
Perform the Power-On Self Test.
Syntax
$PAMTC,POST*hh<CR><LF>
The LB150 WeatherStation will reply with a sentence in the following form:
$PAMTR,POST,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,
<9>,<10>,<11>,<12>,<13>,<14>,<15>,<16>,<17>*hh<CR><LF>
Each of the fields <1> through <14> contains an integer value that represents the status of
a simple test performed on a given submodule within the LB150 WeatherStation. For
each field, a value of 0 (zero) indicates the unit passed the respective test; a nonzero
value indicates a possible problem was discovered with the given submodule. Therefore,
a properly operating unit (with all connected options) would reply with
$PAMTR,POST,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,PB200. . A standard LB150 would output
$PAMTR,POST,0,0,0,0,0,0,0,0,0,0,0,0,,,,0,PB200, where a Null field indicates sensor not
present.
The fields and their corresponding submodules are listed below.
where
<1> = Internal communication between microprocessors
<2> = Format code
<3> = Factory EEPROM
<4> = User EEPROM
<5> = Air temperature sensor
<6> = Plate temperature sensor
<7> = Standard relative humidity sensor
<8> = Barometric pressure sensor
<9> = Wind sensor
<10> = Compass sensor
<11> = GPS receiver
<12> = Attitude sensor
<13> = Rate gyro
<14> = Optional Galltec relative humidity sensor
<15> = Internal temperature Sensor
<16> = Battery voltage Sensor
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<17> = “PB200” string that indicates POST results are for the class of product
described in this specification.
Notes
The various tests performed for the POST function are simple tests to determine if
the hardware is minimally responding to software stimuli. The POST function
should not be regarded as a comprehensive indicator that a given unit is healthy.
In other words, it is possible that a defective unit might still pass the POST
operation. However, the POST can be useful to identify certain types of problems
with the WeatherStation.
Certain models of the WeatherStation may omit some features in the hardware. In
this case, the corresponding fields in the POST sentence will be null (blank)
fields.
The Power-On Self Test is performed automatically a few seconds after applying
power to the unit.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,QPS
Summary
Query part number and serial number information.
Syntax
$PAMTC,QPS*hh<CR><LF>
The LB150 WeatherStation will reply with a sentence in the following form:
$PAMTR,QPS,<1>,<2>*hh<CR><LF>
where
<1> = Part number string (up to 32 ASCII characters)
<2> = Serial number string (up to 32 ASCII characters)
Notes
The part number and serial number strings may not contain the following
characters:
"$"
(dollar sign)
","
(comma)
"*"
(asterisk)
""
(space)
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,QV
Summary
Query version information.
Syntax
$PAMTC,QV*hh<CR><LF>
The LB150 WeatherStation will reply with a sentence in the following form:
$PAMTR,QV,<1>,<2>,<3>,<4>,<5>,
<6>,<7>,<8>,<9>,<10>*hh<CR><LF>
where
<1> = Null field
<2> = Hardware version
<3> = OEM option
<4> = Null field
<5> = Bootloader 1 firmware version
<6> = Application 1 firmware version
<7> = Bootloader 2 firmware version
<8> = Application 2 firmware version
<9> = GPS module version
<10> = Compass module version
Notes
In the earlier model WeatherStation, the PB100, fields <1> and <4> in the reply to
this command contained the 12-character part number and serial number fields,
respectively. In the model LB150, the part number and serial number fields have been
expanded to 32 characters to harmonize them with their NMEA 2000® equivalents.
Because this would have caused this sentence to exceed the 82-character NMEA 0183
limit, these fields in the LB150 must be read using the $PAMTC,QPS command.
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$PAMTC,RESET
_NMEA 0183 RECEIVED SENTENCE_
Summary
Reset the LB150 WeatherStation.
Syntax
$PAMTC,RESET*hh<CR><LF>
The WeatherStation will reset as though power had been removed and reapplied. All
settings will revert to their power-on defaults.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTC,SIM
Summary
Turn Simulate Mode On or Off.
Syntax
One of the following forms:
$PAMTC,SIM,0*hh<CR><LF>
Turn Simulate Mode Off
(default state).
$PAMTC,SIM,1*hh<CR><LF>
Turn Simulate Mode On.
$PAMTC,SIM,Q*hh<CR><LF>
Query Simulate state.
The $PAMTC,SIM,Q command provides a query function to allow reading the current
Simulate state. The reply to the $PAMTC,SIM,Q command is one of the following:
Notes
$PAMTR,SIM,0*hh<CR><LF>
Simulate Mode is Off
$PAMTR,SIM,1*hh<CR><LF>
Simulate Mode is On
The Simulate Mode is not stored in EEPROM. On power up, the Simulate Mode
returns to the Off state.
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_NMEA 0183 RECEIVED SENTENCE_
$PAMTX
Summary
Suspend and resume transmission of NMEA sentences.
Syntax
Fields
$PAMTX,<1>*hh<CR><LF>
<1>
0 = temporarily suspend transmission of all NMEA sentences. (default)
1 = resume transmission
Notes
Upon receiving this sentence, the LB150 WeatherStation will suspend
transmission of all future NMEA sentences after the currently transmitting
sentence has completed.
If the $PAMTX command is received with no fields present (i.e.
$PAMTX*50<CR><LF> or $PAMTX<CR><LF>, the default case shall prevail,
i.e. transmission of sentences will be suspended.
Transmission of NMEA sentences will resume when one of the following has
occurred:
• A $PAMTX,1 command has been received.
•
The power to the WeatherStation has been cycled.
•
A $PAMTC,RESET command has been received.
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3.
Revision History
Revision 0.001
Date:
Description:
7/6/06
Draft.
Revision 0.002
Date:
Description:
7/24/06
Draft.
Revision 0.003
Date:
Description:
7/31/06
Draft for Airmar internal review and comment.
Revision 0.004
Date:
Description:
9/16/06
Draft.
Revision 0.005
Date:
Description:
10/12/06
Draft.
Revision 0.006
Date:
Description:
3/7/07
Draft.
Revision 0.007
Date:
Description:
3/28/07
Draft.
Revision 0.008
Date:
Description:
Revision 0.009
Date:
Description:
Revision 0.010
Date:
Description:
11/26/07
Draft. Added new proprietary PGNs 126720-49 and 126720-50 and $PAMTC,OPTIONs
4 and 5 for controlling WAAS Satellite selection and Enable GPS Type 0 Messages
parameter selection. Added OPTION 3, enable WAAS. Added Device Temp/Voltage to
POST results and PB200 to end of POST Sentence. Changed Device Temp/Voltage PGN
to 65410. Made $PAMTC,ALT altitude units 0.1 meters. Added note about unsupported
local datum codes.
03/04/08
Draft. Added note to PGN 129029, that fields 16-18 are not present if field 15 is 0.
Changed Heater PGN to Global. Changed Introduction to say 3d MEMS Accelerometer.
03/05/08
Draft. Added Compass User Calibration Sentence and PGN details.
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Revision 0.011
Date:
Description:
Revision 0.012
Date:
Description:
Revision 0.013
Date:
Description:
03/24/08
Draft. Fixed version numbering and revised Compass User Calibration Sentence and
PGN details. Added “damping” fields and resets. Compass User Cal INPROCESS
changed to INPROGRESS.
04/10/08
Draft. Made Heater a Factory enabled option. Updated Wind References in
Meteorological Data PGN. User Compass Cal updates relating to Damping values.
Converted to PB150 document. Made minor changes (added differential settings,
clarified VWT)
08/07/08
Draft. Added HDT and HDG as received sentences.
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