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GPS - Depth - Water Temperature
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Keyboard InterfaceVideo Overlay Units
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| The GPSBOXKBD-XDT GPS - Depth - Water Temperature video text overlay units provide a simple solution for displaying
GPS data together with the data from a separate NMEA depth / water temperature sensor combined with a flexible
text interface. The unit will superimpose a display of latitude, longitude, time, date, speed, heading, depth and
water temperature onto any standard colour or mono composite video signal. Four lines of GPS NMEA data can be displayed
combined with four lines of text which can be edited from a PS/2 keyboard and positioned as a block on the screen.
Two models are available. The GPSBOXKBDPLUS-XDT has an internal GPS receiver with an external antenna to provide
the GPS data for the overlay. The GPSBOXKBD-XDT model is designed to be compatible with any external GPS receiver
which sends data using the NMEA 0183 standard. |
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| No keyboard is included. Order the FLEXKYBD item for use with these units. |
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| The GPSBOXKBD-XDT unit can be used with any GPS receiver with NMEA 0183 RS232 serial output. 4800 baud 8N1. |
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The units are housed in an aluminum enclosure with phono connectors for video in / out, a 2.1mm DC power socket
and a power switch. Keyboard connection is via a 6-pin mini DIN socket for a PS/2 keyboard. These units will only
work with standard PS/2 keyboards and USB keyboards which implement PS/2 functionality. They will not work with
USB only keyboards which require PC operating system support. The external GPS receiver's PC connection cable
goes into the GPSBOXKBD-XDT's upper male DB9 connector. |
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The GPSBOXKBD-XDT unit is designed to be used to display depth / water temperature for marine
survey applications.
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| The data position on each line is fixed, but each line can be moved to any line location on the screen or hidden
dependent on the user requirement. The speed over ground display can be switched between knots and kilometres per
hour. The character background can be toggled on and off. The date can be shown in either the standard DD/MM/YY
format or the North American MM/DD/YY format. The time is displayed according to a user selected +/- 12 hour timezone
offset from the GPS UTC time. The character size cannot be changed by the user, although some customisation
of the character set is possible. Please contact us before you make your order for details of customisation.
The gps data display configuration cannot be changed. The depth is displayed in metres. The water temperature is
displayed in degrees centigrade. |
| The table below summarises the data types and user selectable options displayed by the unit, with the NMEA data
sentence each is derived from. If you are unfamiliar with the serial output of the GPS receiver you intend to use
with the GPSBOXKBD-XDT unit you should connect it to a PC and use hyperterminal to check that the XXRMC
and XXVTG data sentences are transmitted. If they are not refer to the documentation from your receiver's manufacturer
for the method required to enable NMEA output. Data sentences other than XXRMC and
XXVTG should be turned off. |
| Data type |
Data sentence required |
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Latitude |
$XXRMC |
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Longitude |
$XXRMC |
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Time ( User selected timezone offset ) |
$XXRMC |
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Date ( DD/MM/YY or MM/DD/YY format ) |
$XXRMC |
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Heading ( Track made good, degrees true ) |
$XXRMC |
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Speed over ground ( in knots or kph ) |
$XXRMC, $XXVTG |
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Depth ( in metres ) |
$XXDBS, $XXDBT, or $XXDPT. See below |
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Temperature ( in degrees centigrade ) |
$XXMTW |
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Depth Data Sentences |
| The lower male DB9 socket of the GPSBOXKBD-XDT is the separate RS232 serial input for an NMEA depth / water temperature
sensor. The unit can read one of three different NMEA depth data sentences, XXDBS, XXDBT or XXDPT. Some devices
will transmit all three, but many will only have one or two. Please check the manual for your device, and if possible,
confirm its serial output using hyperterminal to see which sentence(s) are available in your case. The GPSBOXKBD-XDT
unit will default to display the depth from the $XXDBS if this is present. The other depth data sentences will
be ignored if they are present. If $XXDBS is not present then the depth from $XXDBT will be displayed if this is
present, otherwise $XXDPT would be displayed. |
| Each of the data sentences reports the depth in a slightly different way. Therefore it is important to know which
data sentence(s) are generated by your depth sensor and which is used for display. The table below summarises the
NMEA sentences which can be read and the data from each that will be displayed by GPSBOXKBD-XDT in order of precedence
for display. Please note that the XXDPT sentence reports the depth as two figures, a combination of the depth measured
and an offset, either positive or negative, that you may be able to enter into the receiver or sensor. This allows
adjustment of the measured depth to either the keel or waterline as required. The GPSBOXKBD-XDT unit ignores this
offset. The depth reported in feet and fathoms is also ignored. The depth can only be displayed in metres. |
| Depth data sentence |
Depth displayed as: |
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$XXDBS,35.4,f,10.8,M,5.9,F |
Depth below surface in metres. ( feet and fathoms ignored ) |
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$XXDBT,25.5,f,7.8,M,4.2,F |
Depth below transducer in metres. ( feet and fathoms ignored ) |
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$XXDPT,7.8,3.0 |
Depth below transducer in metres. ( offset in metres ignored ) |
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| Suitability |
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| The GPSBOXKBDPLUS-XDT unit is suitable for a wide range of waterborne visual survey tasks. However it should be
understood that the unit will not always provide a continuously stationary display when the unit is stationary.
Even when a GPS receiver is stationary each calculated position can be different from the last due to the sources of error in the GPS system which limit positional accuracy. These errors will give
the appearance of random motion of the GPS receiver when stationary or occasional jumps in speed when stopped.
Therefore if you will be operating at very low speeds below 0.5 knots you should use GPSBOXKBD-XDT with an appropriate
external GPS receiver. |
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| GPSBOXKBD-XDT |
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Four lines of 26 characters, font and character size fixed |
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UK English or US / International English keyboard mapping available* |
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Compatible with colour and mono composite video signals. 1Vp-p. PAL or NTSC |
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Dimensions 110 x 110 x 45mm LxWxH |
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Power supply required 9 - 12V DC |
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Power consumption 50mA (without keyboard) |
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Operating Temp. 0° - 85°C |
| *All units are shipped with US / International English keyboard mapping unless ordered from the UK. |
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| GPSBOXKBDPLUS+XDT |
GPS Receiver with external Antenna* |
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High performance MTK GPS chipset |
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Very high sensitivity (Tracking Sensitivity: -165 dBm) |
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Rapid Time To First Fix at low signal level, Cold start average 41 seconds, Hot start average 1 second |
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WAAS & ENGOS supported |
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Position Accuracy 10 meters 2D RMS, 5 meters 2D RMS WAAS enabled |
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Datum WGS-84 |
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| The GPSBOXKBD-XDT is designed to be used with separate GPS and depth sensors. However if you require the flexibility
to also use the unit with devices which produce a single combined GPS and depth serial data output you can order
the DUALDB9 adaptor. This allows a single RS232 data stream which includes both NMEA GPS and depth data sentences
to be split between the two inputs of the GPSBOXKBD-XDT. |
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| Mounting Brackets for GPSBOXKBD units. |
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| BNC CONNECTORS |
| All the GPSBOX units can be supplied with BNC connectors on request. Please email
us prior to ordering. |
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© The BlackBoxCameraTM Company Limited 2011
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