Furuno NX-700A manual Principle of Navtex System, How Navtex Works, Navtex System Operation

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1.PRINCIPLE OF NAVTEX SYSTEM

1.1How NAVTEX Works

NAVTEX is an acronym meaning Navigational Telex, and as its name shows, it is a kind of narrow band radio teletype system for sending (by frequency shift keying) text messages expressed in a 7-unit code. The difference is that a NAVTEX transmitter transmits nine control characters (header code) ahead of the main message, so that the receiver can identify the station, message type and serial number automatically.

1.2NAVTEX System Operation

For navigation purposes, the world is divided into 16 areas as shown in the figure below. Each Navtex station has an identification code, from “A” to “Z”. The frequency assigned to Navtex are 518 kHz and another (490 or 4209.5 kHz), and many stations exist in the same service coverage.

If the stations were to transmit without any rule, the system would collapse due to mutual interference. To avoid this problem, the following rules apply.

•The transmission schedule is determined so that two or more stations having a common service area may not overlap in time.

•Each station transmits with minimum required power to cover its service area (200 to 400 nautical miles nominal).

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Contents Navtex Receiver 00015280401 Important Notice Safety Instructions Safety information for the Installer Forword Features Table of Contents Vii Name Type Code No Qty Remarks Equipment ListsName Type Code No Qty Optional SupplyPower supply System ConfigurationsPower supply 100-115 12-24 VDC NX-700B NX-700A NX-7H Max mHow Navtex Works Principle of Navtex SystemNavtex System Operation Nnnn Message FormatNavtex Station Map Navtex Station List III NAV Latitude Longitude Freq Area Station Broadcast schedule UTC XII Operating Controls OperationTurning the Unit On/Off Display unit, front viewAll message display 518 kHz Adjusting LCD DimmerSAR Search and Rescue message Confirming the New MessageOther messages Message list Detailed message Sample MessagesSystem Display Service Choosing the Receive ModeMenu AutoChoosing the Local Frequency Editing the Settings for Station and MessageLocal channel options Rcv Station & MsgStation Rcv Station & Msg AutoMessage Edit window ex. Rcv Station & MsgAlarm Messages Switching the Frequency to Display518 Press 490 Choosing messages to display Processing MessagesList options Urgent messagePrinting Messages Alarm Messages User Messages Good Messages Lock MessageProtecting message from deleting Printing all messages displayedOff All Canceling printingPrinting each message Printing messages automaticallyINS Output Speed Editing the Navtex Station List518kHz NavAreaLongitude 00E 518kHz ID1 ID2 ID3 Latitude 00N490kHz ID1 ID2 ID3 4209.5kHz Range 400nm Save data ?Station Oostende OostendeLatitude 11N Longitude 48E 518kHz ID1 T ID2 ID3Icon Status Meaning Status icon shown at the tip of display IconsMessage icon shown next to messages Message Meaning Remedy Messages ListNavtex menu Other FunctionsSystem menu Skips to $$ Display menu Description SettingNav Data DistanceINS Service menu Description SettingThis page is intentionally left be blank Maintenance Maintenance & TroubleshootingMaintenance program Check point RemedyBattery Replacement of Fuse, Battery and Thermal PaperFuse LCD DisplayThermal paper NX-700A only SELET/READY TroubleshootingMemory test DiagnosticsKey test Rx test Restoring all Default SettingsDisplay Unit InstallationTabletop, overhead mounting For NX-700A Flush mountingFor NX-700B General mounting considerations Receiver UnitMounting Method Mounting considerations Antenna UnitPrinter NX-700B only WiringReceiver unit, inside view Receiver unitTTYCS-1Q For Navigator or INS How to use J402 and 403 connectorFor RG-10/UY, RG-214 cable Antenna cableExtending antenna cable length OP04-2 To Receiver unit FMA-1 connectorGrounding System Setting of PrinterNone Upright InvertedPriority Digital InterfacingGLL Latitude and longitude RMC Recommend Minimum Specific Gnss Data ZDA Time and date NMK Set Navtex mask NRQ Request Navtex messagesACK Acknowledge $--ACK,xxx*hhCRLF Local alarm numberidentifier ChecksumVTG Course over ground and ground speed VHW Water speed and headingVBW Dual ground/water speed Output data description NRX New Navtex received message Serial Interface ALR Set alarmsNavtex Menu TreeFuruno Specifications of Navtex Receiver Furuno Ｐａｃｋｉｎｇ Ｌｉｓｔ NX-700B/NX-700B-HK NX-7001-AN-J*/E*,NX-7001-BN-J*/E NX-7001-AA-J*/E*、NX-7001-BA-J*/E NX-7H-0-10/-10-HK,NX-7H-0-20/-20-HK 工事材料表 004-514-530 08AW-X-9402 004-514-540 08AW-X-9403 08AW-X-9407 004-514-610 08AW-X-9404 Spare Parts List for Page Page Page Page Page 空中線部 外寸図 ナブテックス受信機 Processing Index

NX-700A specifications

The Furuno NX-700A is an advanced navigation system designed specifically for professional mariners and commercial vessels. Known for its robust performance and precision, it integrates state-of-the-art technology to enhance safety and efficiency at sea. One of the most notable features of the NX-700A is its dual-channel frequency system, which allows for improved target detection and tracking capabilities. This dual-channel operation ensures that the system can differentiate between multiple targets, reducing the risk of collisions and enhancing situational awareness.

Another significant aspect of the NX-700A is its high-resolution display. The system is equipped with a large LCD screen that provides clear and detailed graphical representations of surrounding waters, including navigational aids and potential hazards. The intuitive interface allows for easy operation even in challenging conditions, ensuring that crews can concentrate on their primary task: safe navigation.

Further enhancing the usability of the NX-700A is its advanced GPS functionality. The system employs multi-GNSS (Global Navigation Satellite System) technology, enabling it to obtain accurate position fixes from various satellite constellations, including GPS, GLONASS, and BeiDou. This capability ensures that mariners receive reliable positioning data regardless of their location, which is crucial during navigation in remote areas.

The NX-700A also features robust connectivity options, including NMEA 2000 and NMEA 0183 support. This allows the system to interface seamlessly with other onboard equipment, such as autopilots, engine monitoring systems, and electronic chart plotters. Such integration enhances operational efficiency and aids in maintaining a central command point for navigation.

Marine safety is further bolstered with the NX-700A's built-in man-overboard function, which provides rapid and precise positioning information in emergency situations. The system can also store critical navigational data, which can be accessed quickly during emergencies, contributing to enhanced safety protocols on board.

In summary, the Furuno NX-700A is a sophisticated navigation solution that combines high-resolution displays, advanced GPS technology, dual-channel frequency systems, and robust connectivity. Whether used in fishing vessels, cargo ships, or pleasure yachts, the NX-700A stands out as a reliable tool for enhancing maritime safety and navigation efficiency. With its user-friendly interface and essential features, it embodies the modern requirements of marine navigation technology.
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