JRC JLR-7900 User Manual (English)

Questions and Answers:

W
williamwhiteAug 5, 2025
What to do if JRC JLR-7900 power does not turn on?
- B
  batesfrancisAug 5, 2025
  If your JRC Marine Equipment isn't powering on, first ensure the ship junction box is supplying power by checking the cabling. Also, if applicable, verify the power supply unit cabling is correctly connected (only MID models). If the cabling is fine, inspect and replace the fuse connected to the power cable or the power supply equipment fuse (only MID models) if blown. For LOG models, check the connection. If problems persist, the display unit switch may be broken, and you should consult with JRC or their agents.
J
Juan MillsAug 10, 2025
Why is there no transmission to external devices from my JRC JLR-7900 Marine Equipment?
- R
  Rachael BrowningAug 10, 2025
  If your JRC Marine Equipment isn't transmitting to external devices, start by checking the interface settings to ensure the output settings are configured correctly and that the configured channel is correct. If the problem persists, the DISP-DPU or POWER SUPPLY UNIT may be broken, and you should consult with JRC or their agents.
K
Kristy BryanAug 15, 2025
How to fix JRC Marine Equipment when the dimmers are not interlocked?
- M
  Michael PalmerAug 15, 2025
  If the dimmer on your JRC Marine Equipment isn't interlocked, verify that the RS-485 or Daisy-chain bit rate is correct (Daisy-chain is only for MID models), check that the dimmer group number is correct, and ensure the dimmer unit is correct. Also, check the RS-485 or Daisy-chain connection for any disconnections (Daisy-chain is only for MID models).
J
Jared ToddAug 19, 2025
What to do if JRC JLR-7900 has no reception from the sensor?
- B
  bateskathleenAug 19, 2025
  If your JRC Marine Equipment isn't receiving signals from the sensor, first check the connection cable to ensure it is properly connected. If the connection is secure, the sensor itself may be broken, and you should consult with JRC or their agents.
A
aburkeAug 25, 2025
Why is the alarm sound not generated on my JRC Marine Equipment?
- O
  ofreemanAug 25, 2025
  If you are not hearing the alarm sound on your JRC Marine Equipment, first check the alarm sound setting to ensure it is not turned off. If the setting is correct, the buzzer may be broken, and you should consult with JRC or our agents.
E
Emma MillerAug 29, 2025
How to enable the click sound on JRC JLR-7900 Marine Equipment?
- C
  Crystal SwansonAug 29, 2025
  If you are not hearing a click sound on your JRC Marine Equipment, check the click sound setting to ensure it is not turned off.

JRC JLR-7900 Specifications

General

Brand	JRC
Model	JLR-7900
Category	Marine Equipment
Language	English

Summary

General Information

Multi Information display (MID)

The display unit that receives NMEA data items from various sensors.

Doppler LOG

Measures ship's speed accurately from dead slow to maximum using Doppler shift.

GPS Navigator

High-performance navigation equipment for accurate position fixing using GPS satellites.

Before You Begin

Symbols Used In This Manual

Explains warning signs and their meanings used in the manual and on the equipment.

WARNING LABEL

Advises users to locate and not remove or impair warning labels on the unit.

Section 1 Introduction

1.1 Function

Describes the primary functions of the MID, Doppler Log, and GPS Navigator systems.

1.2 Feature

Highlights the key features of the MID, Doppler Log, and GPS Navigator.

1.3 Components

1.3.1 Standard equipments

Lists the standard equipment included with the MID, Doppler Log, and GPS Navigators.

1.3.2 Options

Details the optional accessories available for the MID, Doppler Log, and GPS Navigators.

1.4 Construction

Display NWZ-4610 (MID/Common)

Provides dimensional drawings and mass specifications for the NWZ-4610 display unit.

1.5 System Configuration

1) MID

Illustrates the system configuration for the Multi Information Display.

2) Doppler Log

Shows the system configuration diagram for the Doppler Log system.

3) GPS Navigator

Depicts the system configuration for the GPS Navigator system.

Section 2 Names and Functions of the Components

2.1 NWZ-4610 Display Unit

Details the names and functions of the controls and displays on the NWZ-4610 unit.

Main Unit (Front)

Identifies the main components on the front panel of the display unit.

Reading the Display

Numeric display screen

Explains the elements and indicators displayed on the numeric screen.

Reading the GPS Display

Section 3 Display Screen

3.1 Display screen

Details the factory-set display screens for the MID system.

2) Doppler Log

Illustrates the display screens for the Doppler Log system.

3) GPS Navigator

Shows the display screens for the GPS Navigator system.

Split screen display

Explains how the screen can be split into 1 to 4 areas for multi-information display.

Enlarged part display

Describes highlighting integer or fractional parts of data on screen.

Section 4 Operation

4.1 Basic Operation

4.1.1 Turning on the power

Details the procedure for turning on the display unit's power.

4.1.2 Starting (Normal)

Describes the normal startup process after self-check.

4.1.3 Starting (Abnormal)

Explains startup behavior when self-diagnosis results are abnormal.

4.1.4 Starting (Abnormal) (GPS)

Covers abnormal startup messages related to GPS configuration mismatches.

4.1.5 Starting (Abnormal-3)

Addresses abnormal startup due to program corruption.

4.1.6 Turning off the power

Details the procedure for turning off the display unit's power.

4.1.7 Adjusting the back light (lighting) by using the key

Explains how to adjust display and panel backlight brightness using the keys.

4.1.8 Adjusting contrast

Describes how to adjust the display contrast over 13 levels.

4.1.9 Stopping the Alarm Buzzer

Explains how to stop the alarm buzzer sound.

4.1.10 Alarm display

Describes how alarms are indicated via popup menus and sounds.

4.1.11 Switching displays

Details how to manually cycle through display screens using the key.

4.1.12 Switching display (automatic)

Explains how to set up automatic screen switching with selectable time intervals.

4.1.13 User mode change (MID)

Describes how to change between three user modes, each supporting six screens.

4.1.14 User setting screen display (MID)

Explains how to display user-registered screens for quick access.

4.1.15 Resetting a TRIP (LOG)

Details how to reset the trip distance value, but not the total distance.

4.1.16 Changing a unit of the vessel speed (LOG)

Explains how to switch the vessel speed unit between knots and m/s.

4.1.17 Registering Own Ship's Position (GPS)

Describes how to register the current ship's position into the waypoint list.

4.1.18 MOB (GPS)

Explains the Man Overboard (MOB) function to save and return to a lost position.

4.1.19 Selecting Waypoint/Route with GOTO Key (GPS)

Guides on selecting waypoints or routes using the GOTO key for navigation.

4.2 Menu Operation

4.2.1 Selecting items from the menus

Provides a step-by-step procedure for navigating menus and selecting items.

4.2.2 Entering numeric values

Explains the process for entering numeric values into the unit's settings.

4.2.3 Transitioning to Maintenance Mode

Details how to switch to maintenance mode for initial setup and error prevention.

4.2.4 Setting model

Guides on setting the unit's model, which initializes settings.

4.2.5 Menu Operation List

1) MID

Lists the menu options and settings available for the MID system.

2) System Unit

Details system settings related to units for distance, speed, temperature, depth, and wind.

3) Language

Specifies the available display languages for the unit.

4) Alarm

Configures alarm functions, including sound and LCD color switching.

5) Beacon Setting

Allows setting display preferences for weather information and selecting observation stations.

6) Daisy Chain Setting

Enables the daisy chain function, allowing connection of up to three units.

7) Interface Data I/O

Configures data output formats, ports, bit rates, and sentence versions for interfaces.

8) Maintenance Input Data

Allows viewing received serial port data and selecting display format.

9) Master Reset

Provides options for resetting graphs and the entire display unit.

10) Simulation Mode

Sets up simulated operation types, start dates, times, and positions.

11) Software Update

Allows updating the display unit's software program.

12) Display Type

Sets the model type, which initializes all related settings.

13) RS-485ID

Assigns a unique ID to each display unit on the RS-485 network.

14) Dimmer Group

Links units for synchronized dimmer control via RS-485 network.

15) Dimmer

Selects the method for dimmer control: key or external unit.

2) Doppler Log

Lists menu options and settings for the Doppler Log system.

4) Alarm

Configures alarm behavior for system errors, speed, trip, and sensor status.

5) Sensor Setting

Configures the operation of the signal distributor, including speed correction and output versions.

6) Interface Data I/O

Configures data formats, ports, bit rates for RS-485 and other interfaces.

7) Maintenance Input Data

Allows viewing serial port data and performing diagnostics on components.

8) Master Reset

Resets entire display units, sensor units, or all units.

9) Demo Mode

Selects demonstration types and sets parameters for simulated operation.

10) Soft Update

Allows updating the display unit's program.

11) Main/Sub

Selects the type between Main and Sub.

12) Display Type

Sets the model, which initializes all related settings.

13) RS-485ID

Assigns a unique ID to each display unit on the RS-485 network.

14) Dimmer Group

Links units for synchronized dimmer control via RS-485 network.

15) Dimmer

Selects the method for dimmer control: key or external unit.

3) GPS Navigator

Lists menu options and settings for the GPS Navigator system.

3> Waypoint/Route

Manages waypoints and routes, including registration, selection, and deletion.

4) System Unit

Configures system settings for units, magnetic correction, date, and geodetic datum.

5) Language

Specifies the available display languages for the unit.

6) Alarm

Configures alarm behavior for system errors, speed, trip, and position-related events.

5) Sensor Setting

Configures GPS sensor settings like mode, HDOP, smoothing, and initialization.

9) Interface Data I/O

Configures data formats, ports, bit rates for interfaces including NMEA, IEC, and JRC.

10) Maintenance Input Data

Allows viewing serial port data and performing diagnostics on components.

11) Setting Initialization

Resets display units, sensor units, or all units to factory defaults.

12) Simulation Mode

Sets up simulated operation types, start dates, times, and positions.

13) Software Update

Allows updating the display unit or sensor program.

14) Display Type

Sets the model type, which initializes all related settings.

15) Receiver No.

Selects the receiver number for system configuration.

16) Model Change

Changes the unit's model, which initializes all related settings.

17) RS-485ID

Assigns a unique ID to each display unit on the RS-485 network.

18) Dimmer Group

Links units for synchronized dimmer control via RS-485 network.

19) Dimmer

Selects the method for dimmer control: key or external unit.

20) CCRP

Sets the CCRP and receiver position relative to the ship's coordinate system.

4.2.6 Display category and contents

Lists display categories and their contents for various screen segmentation options.

1) MID

Details display categories and contents for MID screens across different segmentations.

2) Doppler Log

Lists display categories and contents for Doppler Log screens.

3) GPS Navigator

Lists display categories and contents for GPS Navigator screens.

Section 5 Maintenance

5.1 Daily Maintenance

Provides guidelines for routine cleaning and inspection of the equipment.

5.2 Alarm

Lists alarm messages, their causes, and associated message numbers.

5.3 Troubleshooting for Malfunctions or Abnormalities

Offers solutions for common problems and malfunctions with the equipment.

5.3.2 Repair Units

Identifies repairable units and their model numbers for replacement.

5.3.3 Regular Replacement Parts

Lists parts that require regular replacement and their estimated lifespan.

Section 6 Installation

6.1 Affixing Display Unit Nameplate Labels

Details the process of applying product and model identification labels to the display unit.

6.2 Display Unit Installation

Provides instructions and precautions for installing the display unit.

6.3 GPS Receiver Installation

Guides on selecting the optimal position and procedure for installing the GPS receiver.

6.4 Doppler Log Installation

Refers to the Doppler Log service manual for installation procedures.

6.5 Cable Connection

Details the cable connections for the main unit's rear connectors.

6.6 Optional Peripheral Connection

Explains how to connect optional devices like the dimmer unit.

6.6.1 Dimmer Unit Connection

Details the connection procedure for the dimmer unit to control backlight brightness remotely.

Section 7 After Service

7.1 Warranty

States the standard warranty period for the product.

7.2 Repair Parts Stocking Period

Informs about the availability period for functional repair parts.

7.3 When Requesting Repair

Provides instructions on how to contact support and data needed for service.

7.4 Recommendation for Periodic Maintenance

Suggests periodic maintenance checks to ensure optimal performance.

Section 8 Disposal

8.1 Disposal of This Unit

Advises users to follow local laws and regulations for equipment disposal.

8.2 Disposal of Used Batteries

Provides guidance on the safe disposal of lithium batteries found in GPS sensors.

Section 9 Specifications

9.1 Display Unit

Details the technical specifications of the display unit, including basic and environmental.

3) External Interfaces 3-1) MID

Specifies the serial communication and contact signal interfaces for the MID.

9.2 Doppler Log

Lists the basic and environmental specifications for the Doppler Log system.

9.3 JLR-4341 DGPS Receiver

Details the basic and environmental specifications for the JLR-4341 DGPS receiver.

9.4 JLR-4340 GPS Receiver

Lists the basic and environmental specifications for the JLR-4340 GPS receiver.

Related product manuals

JRC JLR-7900 User Manual

Table of Contents

Questions and Answers:

JRC JLR-7900 Specifications

Summary

General Information

Multi Information display (MID)

Doppler LOG

GPS Navigator

Before You Begin

Symbols Used In This Manual

WARNING LABEL

Section 1 Introduction

1.1 Function

1.2 Feature

1.3 Components

1.3.1 Standard equipments

1.3.2 Options

1.4 Construction

Display NWZ-4610 (MID/Common)

1.5 System Configuration

1) MID

2) Doppler Log

3) GPS Navigator

Section 2 Names and Functions of the Components

2.1 NWZ-4610 Display Unit

Main Unit (Front)

Reading the Display

Numeric display screen

Reading the GPS Display

Section 3 Display Screen

3.1 Display screen

2) Doppler Log

3) GPS Navigator

Split screen display

Enlarged part display

Section 4 Operation

4.1 Basic Operation

4.1.1 Turning on the power

4.1.2 Starting (Normal)

4.1.3 Starting (Abnormal)

4.1.4 Starting (Abnormal) (GPS)

4.1.5 Starting (Abnormal-3)

4.1.6 Turning off the power

4.1.7 Adjusting the back light (lighting) by using the key

4.1.8 Adjusting contrast

4.1.9 Stopping the Alarm Buzzer

4.1.10 Alarm display

4.1.11 Switching displays

4.1.12 Switching display (automatic)

4.1.13 User mode change (MID)

4.1.14 User setting screen display (MID)

4.1.15 Resetting a TRIP (LOG)

4.1.16 Changing a unit of the vessel speed (LOG)

4.1.17 Registering Own Ship's Position (GPS)

4.1.18 MOB (GPS)

4.1.19 Selecting Waypoint/Route with GOTO Key (GPS)

4.2 Menu Operation

4.2.1 Selecting items from the menus

4.2.2 Entering numeric values

4.2.3 Transitioning to Maintenance Mode

4.2.4 Setting model

4.2.5 Menu Operation List

1) MID

2) System Unit

3) Language

4) Alarm

5) Beacon Setting

6) Daisy Chain Setting

7) Interface Data I/O

8) Maintenance Input Data

9) Master Reset

10) Simulation Mode

11) Software Update

12) Display Type

13) RS-485ID

14) Dimmer Group

15) Dimmer

2) Doppler Log

4) Alarm