Evaluation Manual for the Use, Operation and Maintenance of GPS Satellite Navigators

Assessment Task Full Details - 100% Full Entry

I. Brief description of contents

(i) Assessment missions

Proper operation and maintenance of GPS satnavs.

(ii) Assessment of implementation

1. Assessment modalities:Select a certain model of GPS Satellite Navigator to turn on and locate normally.
2. Description of the mission (scenario):Operation and maintenance of GPS satellite navigators.
3. Assessment procedures:(1) Basic operation of GPS satellite navigator; (2) Interface setting; (3) Connection with other devices.
4. Assessment of requirements:Normal positioning; basic operation; port setup and smooth signaling to other devices.
5. Breakout groups and timing:Done individually; no more than 10min.

(iii) Elements and criteria for assessment

1. Basic operations:Switch on and off the machine correctly; determine if it is accurately positioned.
2. Interface settings:Set up NEMA 0183/2000 or RS-232/422 output ports; interpret important statements: GLL, ZDA, etc.
3. Equipment connection:Access to signal amplifiers; provide signals through amplifiers for radar, AIS, depth sounder, C-ship stations, VHF and MF/HF DSCs, etc.; detect signals using multimeters or software.

II. Methods of operation

◎ (I) Basic operation of GPS satellite navigator

1. Normal power-up and judgment of positioning

(1) The device is switched on:GP-170 First start up about 1~2min searching for position. Hot start for the same sea area is about 15s.

① Power startup and self-test:Press the “Power” button and check the master unit, receiver module, memory (Flash ROM/SRAM) and backup battery. Check network port and NMEA 0183 connection. Display “SYSTEM OK” or error code.
② Functional mode loading:EXTERNAL SENSOR CONNECTED“ is displayed when configuring an external sensor. Restores the mode before the last power off.

(2) Judgmental positioning:

● Normal mode:2D, 3D, D2D/D3D (differential), W2D/W3D (WAAS).
● Not positioned (NO FIX):Antenna connections, perimeter masking, and electromagnetic shielding need to be checked.

● Accuracy abnormality (DOP warning):
- 3D Mode: PDOP > 6, automatically downgrades to 2D.
- 2D mode: HDOP > 4, antenna optimization required.

Note: When the “DEMO” icon is displayed, you need to turn off the power and press and hold the “NU/CU ENT” key to turn on the power again to return to normal mode.

◎ (ii) GPS Satellite Navigator Interface Setup

(1) Set the output port and explain important statements:

① MENU/ESC → [7 I/O] → [1 Output Data1] → [1 Mode]: Select [1 IEC/NMEA] or [2 RTCM].
② [2 Format]: Select IEC 61162-1 Ed.4/5, Ed.3, NMEA V2.0 or V1.5.
③ [3 Talker]: SOLAS ships select [1 Auto], or select [2 GP], [4 GN].
④ [4 bps]: Select 4800, 9600 or 38400 bps.
⑤ [5 Sentence]: Selects the statement (GGA, GLL, GNS, RMC, VTG, etc.) and sets the TX interval (0.1s* to 90s).
*Note:38400 bps for GGA, GLL, GNS, RMC, VTG only. load rate should be kept below 100%.

Important statements paraphrased:
ZDA-UTC Date/Time/Time Zone;GGA-GPS positioning data (accuracy/number of satellites/DOP, etc.);GLL-Geodetic coordinates;VTG-Ground speed information (SOG/COG);RMC-Recommended minimum data format;AAM-Waypoint arrival alarm.

:: (iii) Connecting GPS sat-navs to other equipment (key element)

GPS output signal needs to be connected tosignal amplifierAmplify and distribute, connect to AIS, gyrocompass, radar, VDR, etc. Determine the type of data required for the external device prior to operation (Talker code must be consistent).

Physical interface specifications:
- RS-232:Proximity transmission (within 15m), 3 out of 9 pins for I/O.
- RS-422:Long distance transmission (tens of meters or more), 5 out of 9 pins for I/O.
Connections need to be tight, cables free of damage, and ground shield integrity checked to avoid interference.

Validation Methods:Compare the boat position information displayed by the external device with that of the GPS main unit. Or use theMultimeter DC 5V stopMeasurement output signal: If the reading is 0.5 to 1.5V Oscillation between indicates normal output.

GPS Satellite Navigator Evaluation Practice Pocket Guide

ETO Assessment Quick Check - Operating Procedures - 100% Detail Retention

1. Rapid determination of positioning status (assessment item 1)

Show Icons	Assessment of the meaning of the determination
3D / D3D	Three-dimensional positioning (4+ stars) in optimal condition.
2D / D2D	2D positioning (3 stars), highly unreliable only.
NO FIX	Not localized, need to check antenna, masking or EM shielding.
DOP	Precision exceeds limits (PDOP>6 or HDOP>4).

2. I/O Interface Setup Flow (Evaluation Item 2)

Path: MENU → 7 I/O → 1 Output Data 1

● Mode. IEC/NMEA ● Format. Ed. 4/5 or V2.0
● Talker. Auto (SOLAS ships) or GP/GN
● BPS. 4800 (Standard) / 38400 (High Speed)

NMEA statement shorthand: GLL (coordinates), ZDA (time), VTG (velocity), GGA (full volume positioning), RMC (minimum data).

3. Connection and testing key points (Assessment 3)

Physical wiring: RS-232 (<15m) or RS-422 (long range) to ensure shielding is intact.
Signal Measurement: Using a multimeter DC 5V Block Measure the NMEA output.
Normal phenomenon: The pointer/reading is at 0.5V to 1.5V Regular oscillations between.
Data reconciliation: Check that the latitude and longitude displayed by the radar and AIS are synchronized with the GPS host.

💡 Assessing Emergencies Tips

Display the DEMO: Turning off the power → Press and hold [NU/CU ENT] → Power on recovery.
The load is too high: Ensure that the output load factor is < 100% (reduce non-essential statements).
Antenna alarm: Check for rusted BNC/TNC connectors or broken cables.

Code of Practice for Marine Electrical and Electronic Operators | Revised 2026

GPS Satellite Navigator Hands-on Evaluation Simulation Score Sheet

Suitable for: Ship's Electrical and Electronic Operator (ETO) | Assessment Duration: 10min | Total Marks: 100

Element 1: Basic Operations and Positioning Judgment (30 marks)

Assessment rules and standard actions	value of a score	score
1.1 Switch on and off correctly: Press the Power key and observe the hardware self-test prompt (SYSTEM OK) on the screen.	10
1.2 Status determination: Be able to accurately state the meaning of 2D, 3D, D3D positioning modes and the number of stars required.	10
1.3 Exception Handling: Identify the cause of a DOP warning; demonstrate how to exit demo (DEMO) mode.	10

[Image of Furuno GP-170 hardware diagnostic screen showing self-test status]

Element 2: Interface Setup and Interpretation of Statements (30 marks)

Assessment rules and standard actions	value of a score	score
2.1 Port Setting: Successfully enter the I/O menu and set Talker (Auto/GP) and Baud Rate (4800/38400).	15
2.2 Interpretation of Statements: Be able to explain orally the function of GLL, ZDA, GGA, RMC, VTG statements.	10
2.3 Load Limit: Specify that the load factor must be kept below 100% for TX interval setting.	5

[Image of a digital bridge console showing GPS data integration on an ECDIS screen]

Element 3: Device Connectivity and Signal Detection (40 points - key item)

Assessment rules and standard actions	value of a score	score
3.1 Physical Wiring: Connect the GPS to the signal amplifier, making sure the shield is grounded and the connections are not loose.	15
3.2 Signal Measurement: Using a multimeter with a DC voltage step, the signal is observed to oscillate within the range of 0.5 to 1.5V.	15
3.3 Synchronization: Confirmation on the radar/AIS side that the read coordinates are identical to the GPS host data.	10

[Image of a marine technician using a multimeter to check NMEA 0183 output at a terminal block]

Evaluator Comments:

Total Score

/ 100