Furuno DS 80 Service Manual [PDF]

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DOPPLER SPEED LOG Marine Speed and Distance Measuring Equipment (SDME) MODEL



DS-80



PRINTED IN JAPAN



C



Yo u r L o c a l A g e n t/D e a le r 9-52, A shihara-cho, N ishinom iya, Japan Te l e p h o n e : Te l e f a x :



0 7 9 8 -6 5 -2 111 0798-65-4200



A ll rig h ts re s e rv e d .



Printed in Japan



PUB. No. SM E-72470-A ( M AYA )



DS-80



FIRST



EDITIO N



:



OCT



2000



CONTENTS FEATURES………………………………………………… 1 PRINCIPLE………………………………………………… 2 EQUIPMENT LISTS……………………………………… 3 SPECIFICATIONS………………………………………… 5 1. SYSTEM CONFIGURATION………………………….. 7 2. FUNCTION OF EACH UNIT…………………………... 8 3. POWER SUPPLY CIRCUIT……………………………. 9 4. TRANSMISSION………………………………………… 12 5. RECEIVING CIRCUIT……………………………….….13 6. PARTS LOCATIONS……………………………………..15 7. ADJUSTMENT/SETTINGS…………………………….. 20 7.1 Transducer Adjustment……………………………………20 7.2 Setting of Maximum Speed Range………..………………21 7.3 Setting for Analog Display……………………………….. 22 8. TROUBLSHOOTING…………………………………… 23 8.1 Diagnostics, Checking ID Program………………………. 23 8.2 Checking the Interconnection……………………………. 25 9. DIGITAL INTERFACE (IEC 61162-1)…………………. 26



MECHANICAL PARTS LIST …………………………



D-1



ELECTRICAL PARTS LIST …………………………… E-1 SCHEMATIC DIAGRAM Interconnection Diagram…………………………………….. S-1 Display Unit Schematic Diagram……………………………. S-2 Transceiver Unit Schematic Diagram…………………………S-3 Distribution Box Schematic Diagram……………………… S-4/S-5 Circuit Diagram of Transceiver Unit………………………S-6 to S-8 Circuit Diagram of Display Unit……………………………S-9/S-10 Circuit Diagram of Distribution Box………………………S-11 to S-15 Transducer…………………………………………………….S-16



FEATURES The FURUNO DS-80 displays ship’s speed relative to water, using the Doppler principle; ship’s speed is measured by detecting the Doppler shift frequency from the signal returned from the water-mass. The output is interfaced with ARPA, AIS, and other ship-borne equipment in IEC 61162-1 format. The main features of the DS-80 are simple operation. In most cases all that is required to display ship’s speed is to turn on the equipment. Pair-beam system effectively reduces error caused by pitching. The transducer assembly symmetrically emits two sonic beams, one fore and the other aft. By averaging the Doppler shift in both directions accurate speed data is available under rough sea conditions. Speed and distance information on the adjustable-contrast LCD display. Analog display, digital Indicator and digital distance indicator display optionally available. Complies with IMO Res. A.824(19) and IEC 61023: 1997.



1



PRINCIPLE The doppler sonar measures ship's speed by using the principle of the Doppler effect, which defines that a signal emitted from a moving object is heard with its frequency shifted at stationary locations and the degree of the frequency shift is proportional to the speed of the moving object. For ease of understanding measurement of ship's fore-aft speed is explained. The DS-80’s two-pair beam system is illustrated in the figure at right. Ultrasonic waves are emitted at an angle of relative θ to water line toward ship's fore and aft directions. If the ship's speed is V, the source of the ultrasonic wave (transducer) approaches or goes away from the reflecting points on the seabed at a speed of Vcosθ. This relative motion causes the Doppler shift and the ultrasonic waves reflected at the seabed are received at frequencies of fo + fd and fo – fd by the transducer. A processor in the DS-80 computes the difference of fo + fd and fo – fd to extract only the Doppler shift factor fd. fo + fd – (fo – fd) = 2fd



Since the fd is theoretically given by fd = 2Vcosθ x fo/C (C: Sound velocity in water) and fo, C and θ are known, V can be calculated if the fd is given. fd = 2Vcosθ fo C



Note that the sound velocity in water changes with water temperature and water pressure but the change by water temperature is automatically compensated by using temperature sensor. V



θ



fo-fd



V θ V cosθ



2



fo fd



EQUIPMENT LISTS Standard supply Name Main Display Distribution Box



Transceiver Unit Transducer Unit Terminal Box Spare Parts



Installation Materials



Type DS-800 DS-801-100 DS-801-110 DS-801-115 DS-801-200 DS-801-220 DS-801-230 DS-810 DS-820 DS-802 SP65-00700



Code No. 000-029-046



Qty 1



1 1 1 1 set



SP65-00710



000-029-056



1 set



CP65-00900



000-029-047



1 set



1



Remarks 100 VAC 110 VAC 115 VAC 200 VAC 220 VAC 230 VAC



For 115 V, w/SP65-00701, SP65-00702, SP65-00601 For 230 V, w/SP65-00702, SP65-00702, SP65-00601 w/CP65-00901, CP65-00902, CP65-903



Optional equipment Digital Indicator (000-029-020) Name



Type



Code No.



Qty



Remarks



Digital Indicator



DS-830



Spare Parts



SP65-00601



002-889-730



1 set



Fuse



Accessories



FP65-00400



000-029-028



1 set



Installation Materials



CP65-00800



000-029-027



1 set



FP65-00401, FP65-00402, FP65-00403 CP65-00801, MJ-A7SPF-005-020, MJ-A6SPF-003-020



-



Remote Distance Indicator (000-029-022) Name Type Code No. Remote Distance DS-840 Indicator SP65-00601 002-889-730 Spare Parts



1



Qty 1



1 set



Fuse FP65-00401, FP65-00402, FP65-00403 CP65-00801, MJ-A7SPF-005-020, MJ-A6SPF-003-020



Accessories



FP65-00400



000-029-028



1 set



Installation Materials



CP65-00800



000-029-027



1 set



3



Remarks



Optional equipment (con’t) Name Terminal Box Range Switch Box



Dimmer



Junction Box Kingston Seachest



Analog Display



Type DS-802 DS-389 MF-22R-1 MF-22R-2 MF22L-1100V MF22L-1200V MF22L-2100V MF22L-2200V CI-630 TFB-5000 (1) DS-850 DS-781 DS-782 DS-783 DS-784 DS-786 DS-773-A DS-761R-S DS-762R-S MF22A-4



Code No. 000-029-048 000-028-039 000-069-391 000-069-392 000-069-401



Qty 1 set 1 set 1 set 1 set 1 set



000-069-402



1 set for 230 V, flush mount



000-069-403



1 set for 115 V, bulkhead



000-069-404



1 set for 230 V, bulkhead



000-015-206 000-029-050 000-029-051 000-029-052 000-029-053 000-029-054 000-029-055 000-028-960 000-028-975 000-028-976 000-069-384



1 set 1 1 set 1 set 1 set 1 set 1 set 1 set



4



Remarks w/CP65-00903 w/CP66-01000 Flush mount type Bulkhead type for 115 V, flush mount



w/CP66-00703



w/tightening handle Projection type Gate valve, projection type Flush mount, projection type Flush type Gate valve type -10 to +20 knots, flush mount 1 set -10 to +30 knots, flush mount -10 to +30 knots, bulkhead -10 to +30 knots, compact type



SPECIFICATIONS 1. GENERAL (1) Speed Range (2) Distance Run (3) Working Depth (4) Working Frequency (5) Speed Accuracy (6) Distance Accuracy



Fore-Aft: -10.0 to +40 knots through-the-water 0.00 to 999,999.99 nautical miles through-the-water Water depth greater than 3 m beneath the keel. 1.0 MHz 1.0% or 0.1 knots whichever is the greater 1.0% or 0.1 nm whichever is the greater



Note: Accuracy is subject to shallow water effects, to the effect of wind, current and tide, and sensor location. Any ultrasonic equipment having the same frequency may interfere with speed measurement. The Doppler Log transducer should be installed apart from the transducers of such kind of equipment. 2. DISPLAY UNIT (1) Display (2) Indication Ship's speed Distance run (3) Other Function



Character size 15 or 21 mm H on monochrome LCD Fore: ↑ **.* knots (+40.0 max) Aft: ↓ **.* knots (-10.0min) ******.** nm (999999.99 max) Diagnostic check



3. DIGITAL INTERFACE (1) Serial Signal Output: Input: (2) Analog Signal



2 port; VBW, VLW in IEC 61162-1 (NMEA 0183 Verl.5/2.0) 1 port; 1EC61162 (NMEAOI83Ver1.5/2.0) Speed signal for Analog display, 3 port -3.3 mA to 10 mA/-l0 to +30 kt, -3.3 to 10V/-10 to 30kt Analog current output: 1 port, analog voltage output: I port (3) Distance run output Contact closure each 0.005 nm, forward speed, 30 VDC: 0.2 A Pulse wideth: **ms Leading edge: **ms (4) System Check signal 1 port, 30 VDC: 0.2 A, default: closed 4. POWER SUPPLY (1) System Source (2) Rated Current



100/115/120/200/220/230 VAC (+/-10%), 1 phase, 50-60 Hz 115 V: 1.5 A max, 230 V: 0.7 A max.



5



5. ENVIRONMENTAL CONDITION (lEC 60945) (1) Ambient Temperature Analog display 0 0C to +50 0C Others -15 0C to +550C (2) Relative Humidity 95% at 400C (3) Vibration +/-1 mm +/-10%, 2(5) to 13.2 Hz, Maximum acceleration 7 m/s2, 13.2 to 100 Hz (4) Category of Equipment Display Unit! Distance indicator / Transceiver Unit: For protected area, IPX5 Transducer: For submerged area, IPX8, 600 kPa Distributor / Terminal box: For protected area, IPX2 6. COATING COLOR (1) Display Unit (2) Distributor (3) Transceiver Unit (4) Terminal Box (5) Analog Display



Cover: Munsell 2.5GY5/1 .5 (light gray) Panel : N3.0 (gray) Munsell 2.5GY5/1 .5 (light gray) Munsell 2.5GY5/1 .5 (light gray) Munsell 2.5GY5/1 .5 (light gray) Munsell 2.5GY5/1 .5 (light gray)



7. COMPASS SAFE DISTANCE (1) Display Unit, Digital Indicator and Digital Distance Indicator Standard: 0.60 m, Steering: 2.10 m (2) Transceiver Unit Standard: 2.50 m, Steering: 1.40 m (3) Terminal Box, Distributor and Terminal Box Standard: 0.65 m, Steering: 0.45 m VALUES TENTATIVE SAFETY PRECAUTION * There is no unit giving rise to a dose rate > 0.5 mrem/h at 50 mm. * There is no harmful radiation from the screen. * All units of this equipment comply with EMC requirements in lEC 60945.



6



1. SYSTEM CONFIGURATION DISPLAY UNIT DS-800



TERMINAL BOX DS-802 DIMMER MF-22L-1/MF-22L-2 IEC 61162-1 Input Power ON SW Signal Distance Run Signal IEC 61162-1 Output



DISTRIBUTION BOX DS-801



DIMMER MF22L-1/MF22-2



JUNCTION BOX DS-802 JUNCTION BOX CI-630



TRANSCEIVER UNIT DS-810



DIGITAL DISPLAY DS-830 REMOTE DISTANCE INDICATOR DS-840



DIMMER MF-22L-1/MF-22-2



RANGE SWITCH BOX DS-389



115/230 VAC



ANALOG DISPLAY UNIT DS-762/DS-763 /MF-22A-4/MF-22A-9, and others



SHIP'S MAINS 115/230 VAC



: STANDARD SUPPLY



TRANSDUCER DS-820



: OPTIONAL SUPPLY : LOCAL SUPPLY



7



2. FUNCTION OF EACH UNIT DISPLAY UNIT (DS-800) ICP board (65P6000)



• Displays the ship's speed and the distance run. DISTRIBUTION BOX (DS-801) JPW board (65P6010)



• • • • •



Distributes the ship's speed data with NMEA format Outputs a analog ship's speed data for display unit. Outputs a Log Pulse Supplies the power for the optional display unit. Supplies the powers for the transceiver unit



TRANSCEIVER UNIT (DS-810) KCP board (65P6020) • Transmits and receives the signal • Calculates the ship's speed by processing the received signal



TRANSDUCER UNIT (DS-820) LTD board (65P6050) • Matching board



8



3. POWER SUPPLY CIRCUIT The DS-80 is shipped from the factory ready for connection to the ordered AC power supply specified when ordering. To connect to a different AC power supply, change the jumper wiring on the terminal TB5 in the Distribution Box and change the FUSE, as shown in Figure 3.1. Note: From 100 VAC to 200 VAC changing is not available.



Fuse



Terminal Board 100VAC 9 8 7



6



5 4 3



2 1



110VAC 9 8 7



6



5 4 3



2 1



120VAC 9 8 7



6



5 4 3



2 1



7



6



5 4 3



2 1



220VAC 9 8 7



6



5 4 3



2 1



230VAC 9 8 7



6



5 4 3



2 1



200VAC 9 8



Jumper wire



AC power supply and jumper wires on the terminal board in the distribution box



Distribution box, cover removed



AC power supply and fuse 100/110/120VAC 3A(250V) 200/220/230VAC 3A(250V)



Note: Earlier production sets have 1A fuse. It is replaced with 3A fuse if it is blown off.



Figure 3.1. Changing the jumper wiring



Power supply circuit in the Display unit and Distribution Box See the schematic diagram in Figure 3.2. Ship's Main is supplied to the step-down transformer T1 through the power switch S1, fuse F1 and AC filter FL1 in the Distribution Box. Since the power switch S1 keeps on, the 24VDC is always generated from the rectifier circuit composed by CR1/CR2/CR3/CR4, and supplied to the display unit as power supply. When the power key on the display unit is pressed, the output of Q3 (24VDC) activates the photo coupler U2, the relay K1 and K2 on the JPW board in the Distribution Box. Once the relay K1 and K2 become on, the 100VAC/0.1A is supplied to the DC regulator circuit on the JPW board and 100VAC/0.85A is supplied to the Transceiver Unit (DS810). Inspection of the JPW board (65P6010) Measuring Points +5VDC TP18 +15VDC TP19 and TP20(GND) -15VDC TP21 and TP20(GND)



Measured by Digital Multimeter Ditto Ditto



9



Rating 4.75 to 5.25VDC 14.25 to 15.75VDC -14.25 to -15.75VDC



10



Distribution Box



ICP 65P6000



Display Unit



Figure 3.2



Power circuit in the Display Unit and Distribution Box.



JPW 65P6010



Inspection of the ICP board (65P6000) Measuring Points 3VDC 5VDC 24VDC



TP19 TP20 TP3 and TP1



Measured by



Rate



Digital Multimeter Ditto Ditto



3.14 to 3.46VDC 4.75 to 5.25VDC 16 to 32VDC



Power circuit in the Transceiver Unit See the schematic diagram in Figure 3.3. The 100VAC is supplied from the Distribution Box, and applied to 12VDC, 5VDC and +B voltage regulator circuits on the KCP board. KCP 65P6020



Figure 3.3 Power circuit in the Transceiver Unit Inspection of the KCP board (65P6020) Measuring Points +B FUSE F1 +12V TP23 +5V TP24 +5VA TP25



Measured by Digital Multimeter Digital Multimeter Digital Multimeter Digital Multimeter



11



Rating 130 to 150VDC 11.4 to 12.6VDC 4.75 to 5.25VDC 4.75 to 5.25VDC



4. TRANSMISSION See the schematic diagram in Figure 4.1. The transmission pulse having a 1MHz carrier frequency is outputted from the CPU on the KCP board, it's pulse-length and repetition rate are 1ms and 150ms. The transmission pulse is sequentially applied to the buffer "Q3", driver circuit "Q6/Q5", and Power MOS FET amplifier Q2/Q7, then simultaneously outputs to the forward and after transducers through the transformer T5. The transmission output level must be 117 to 143Vpp as shown in Figure 4.2 .



Figure 4.1 Transmission circuit



Measuring point Forward output TB1: #4 and #5 After output TB1: #7 and #8 Figure 4.2 Waveform of the Transmission output at TB1.



12



5. RECEIVING CIRCUIT See the schematic diagram in the Figure 5.2. The received signals from the For./Aft. transducer are individually amplified by the each amplifier circuit "U201/U202 and U204/U205" on the KCP board, and then mixed with the carrier signal by the mixer "Q201/Q202" so as to convert the received frequency into 125kHz +/- fd (IF signal). The IF signals are further amplified by the logarithmic amplifier "U13 and U15", and converted into a square-waves by the comparator U14 and U16. The outputs of the U14 and the U16 are then sent to the CPU circuit where the doppler shifts are measured and calculate the ship's speed.



Inspection Check the waveforms at the test points TP5 and TP10. The waveform at each test point is as follows;



Transmission signal



Echo



v



Noise level Signal level



Figure 5.1 Waveform at the Test Point TP5 and TP10



Note: The noise level should be lower than the "1.0 V" and higher than "0.5 V".



13



14



After Transducer



Forward Transducer



Amplifier



Amplifier



Local Oscillator



Amplifier



Amplifier



Mixer



Mixer



Filter



Filter



Figure 5.2 Receiving Circuit



Filter



Filter



Amplifier



Amplifier



TP5/TP10



Log. Amplifier



Log. Amplifier



Comparator



Comparator



6. PARTS LOCATIONS



Figure 6.1 Display unit , front view



Figure 6.2 Display Unit, rear view



15



FG(GND) ICP board (65P6000)



J2 J1



Figure 6.3 Display Unit, ICP board (65P600)



Transformer T1 AC. Plug



KCP board (65P6020)



Power Switch S1 TB2



Terminal TB1



Figure 6.4 Transceiver Unit (DS-810)



16



Terminal TB5



Transformer T1



JPW board (65P6010)



24V Regulator U1 Relay K1 Fuse F1



AC Filter (inside)



Power Switch S1



Terminal TB4



TB1 TB2 TB3



Figure 6.5 Distribution Box (DS-801)



17



TP25: +5V TP24: +5V(D)



TP22: DGND



TP16: +B



CR22



J3 CR21



FUSE: F1



TP21 S1



TP15



S2 TP3 TP1 TP4 TP2 J1



TP14 J5 TP7:SIG2 TP17:DGND



TP9:DGND TP26:AGND J2



TP16:VLOG2 TP6:SIG1 TP5:VLOG1



CR18 CR17 CR16 CR15



TP20:AGND TP19 TP18



J4



J6 TP23: +12V



TB1



Figure 6.6 KCP board (65P6020)



18



TP15



TP18



S2



U17



TP4



CR9 CR10



R100



R145 CR16 S3 JP8 JP6



TP21 TP20 TP19 TP23 R22 R36 R29 R40 S1 TP7 R96 R88



CR15 CR14 TP22 S4 TP14 ANAV CR21 TP13 ANAC TP16 TP12 TP17



Figure 6.7 JPW board (65P6010)



19



7. ADJUSTMENT/SETTINGS 7.1 Transducer Adjustment Transducer mounted error, which causes incorrect speed value, can be compensated the main display through the menu (Range: -45° to +45°). 1.



Press the [MENU] key to display the main menu. MENU DISTANCE RUN DISPLAY CONTRAST DEMO SYSTEM MENU SYSTEM MENU 2



Figure 7.1.1 Main menu 2.



Select SYSTEM MENU and press the [ENT] key to display the system menu. SYSTEM MENU SHIP SPD AVG SPEED OFFSET TRACK DEPTH XDR OFFSET SPD DATA SELECT



15 SEC - 0.0% 2.0m -00 DOPPLER



Figure 7.1.2 System menu 3. 4. 5. 6.



Select XDR OFFSET and press the [ENT] key. Press !or" to select the digit or sign (+ or -) you want to change; press # or $ to select the digit and +/-. For example, when there is +5° error enter “+05”. Press the [ENT] key. Press the [MENU] key twice to close the menu.



20



7.2 Setting of the Maximum Speed Range Change the maximum range of the connected analog display by setting of DIP switch S2 in the distribution box. Maximum speed S2



20 kt #1: ON Others: OFF



30 kt All: OFF



JPW Board



40 kt #2: ON Others: OFF S2 (Default setting: all OFF)



Distribution box DS-801, inside view



Figure 7.2 Distribution Box, inside view



21



7.3 Setting for Analog Display When the analog indicator is connected, synchronize the speed displays of DS-80 main display unit and analog display as follows. 7.3.1 Connected to TB2 ANA1 (analog 1) 1. Set at 0 knot on the DEMO display, and then adjust R29 in the distribution box so as that the analog display shows 0 knot. 2. Set at 30 knots on the DEMO display, and then adjust R40 in the distribution box so as that the analog display shows 30 knots.



7.3.2 Connected to TB2 ANA2 (analog 2) 1. Set at 0 knot on the DEMO display, and then adjust R27 in the distribution box so as that the analog display shows 0 knot. 2. Set at 30 knots on the DEMO display, and then adjust R36 in the distribution box so as that the analog display shows 30 knots.



7.3.3 Connected to TB2 ANAV (analog voltage signal) 1. Set at 0 knot on the DEMO display, and then adjust R100 in the distribution box so as that the analog display shows 0 knot. 2. Set at 30 knots on the DEMO display, and then adjust R145 in the distribution box so as that the analog display shows 30 knots.



7.3.4 Connected to TB2 ANAC (analog current signal) 1. Set at -10 knots on the DEMO display, and then adjust R87 in the distribution box so as that the current is 4 mA. 2. Set at +30 knots on the DEMO display, and then adjust R96 in the distribution box so as that the current is 20 mA.



Set to OFF.



R36 R27 R29 R40



R87



ON OFF



Power switch: Upper Figure 7.3 Distribution Box Distribution box DS-801



22



R100 R145 R96



8. TROUBLSHOOTING 8.1 Diagnostics, Checking ID Program The diagnostic facility checks the ROM, RAM, SIO and displays program ID. 1. Press the [MENU] key to open the menu. 2. Select SYSTEM MENU2 and press the [ENT] key. SYSTEM MENU2 TEST DIMMER INTERNAL /LANG. ENGLISH



3. Press the [ENT] key. The following display appears. TEST START ? (STOP: PWR OFF) ARE YOU SURE ? YES NO



4. Press the [ENT] key to start the test. In a few moments your display should look something like the one shown below.



The ROM, RAM and SIO (if special connector is connected) are checked for proper operation and the results shown as OK or NG (No Good). For NG, contact your dealer for advice. “PUSH KEY” is highlighted, prompting you to check the controls. Operate any control (except the [POWER] switch) within five seconds of seeing PUSH KEY highlighted. The name of the activated control appears on screen if it is operating normally. Note that if no control is operated within five seconds the equipment automatically begins checking the LCD. Name of control operated appears here. SELF TEST ROM RAM SIO*



No. of times test consecutively executed.



: OK : OK : OK



PUSH KEY (STOP: PWR OFF) CNT: 006 65-5-0100-0XX



XX = Program ver. no. * Requires special connector to test. This location is blank when the connector is not connected.



23



5.



The equipment automatically checks the LCD, displaying the following in order.



ALL ON 2 SEC. ALL OFF 3 SEC.



6. The test repeats itself. To escape from the test, turn the power off and on again.



24



8.2 Checking the Interconnection The equipment do the following to confirm if the doppler speed signal is being output correctly. 1. 2.



Press the [MENU] key to display the main menu. Select DEMO, and press the [ENT] key to display the demo menu.



DEMO SPEED +10.0 kt DATA OUTPUT



OFF



DEMO MODE menu 3. 4. 5.



6. 7. 8. 9. 10. 11.



Select SPEED. Press the [ENT] key. Use the cursor pad to enter the speed value desired. !": Change value, +/#$: Change digit Press the [ENT] key. Select DATA OUTPUT and press the [ENT] key. Press ! to select ON and press the [ENT] key. Press the [DISP] key. Confirm the value displayed is the same as it entered at step 5. Confirm the same as speed is shown on external equipment (radar, GPS, etc.). Select OFF at DATA OUTPUT, and press the [ENTER] key.



25



9. DIGITAL INTERFACE (IEC 61162-1) 1. I/O Sentences Input GGA, VTG



Output VBW, VLW



2. Sentence Description GGA - Global positioning system (GPS) fix data Time, position and fix related data for a GPS receiver. Differential reference station ID, 0000-1023* Age of differential GPS data* Units of geoidal separation, m* Geoidal separation * Units of antenna altitude, m* Antenna altitude above/below mean sea level (geoid)* Horizontal dilution of precision* $--GGA, hhmmss.ss. 1111.11, a, yyyyy.yy, a, x, xx, x.x, x.x, M, x.x, M, x.x, xxxx*hh



Number of satellites in use, 11-12, may be different from the number in view* GPS quality indicator (note 1) Longitude - E/W* Latitude - N/S* UTC of position* NOTES 1



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 GPS fix valid



* Not used.



26



VTG - Course over ground and ground speed The actual course and speed relative to the ground. $--VTG, x.x, T, x.x, M, x.x, N, x.x, K*hh



Speed, km/h* Speed, knots Course degrees magnetic* Course degrees true* *: Not used. VBW - Dual ground/water speed Water-referenced and ground-referenced speed data. $--VBW, x.x, x.x, A, x.x, x.x, A, x.x, A, x.x, A *hh * No use



Status, stern ground speed* Stern transverse ground speed* Status, stern water speed* Stern transverse water speed* Status, ground speed* Transverse ground speed* Longitudinal ground speed* Status, water speed* Transverse water speed* Longitudinal water speed1 , knots NOTES 1. Longitudinal speed: “-” astern. * Not used.



VLW - Distance travelled through the water The distance travelled, relative to the water. S--VLW, x.x, N, x.x, N hh Distance since reset, nautical miles Total cumulative distance, nautical miles



27