True Heading RX Dual-Channel VHF AIS Receiver

Further details of True Heading RX Dual-Channel VHF AIS Receiver

The True Heading Vision RX is a true dual-channel AIS receiver designed to receive and decode AIS transmissions. It can receive messages from AIS Class A and Class B transceivers, AIS-EPIRBs, AIS-SARTs, AIS-MOBs, AIS-AtoNs and AIS base stations. The receiver does not transmit information about the vessel on which it is installed.

True Heading Vision RX dual-channel AIS reception

• Dual-channel AIS receiver
• Fixed reception frequency: 161.975 MHz
• Fixed reception frequency: 162.025 MHz
• Channel bandwidth: 25 kHz
• Receiver sensitivity: better than -112 dBm at 20 percent Packet Error Rate
• Receives AIS Class A transponders
• Receives AIS Class B transponders
• Receives AIS-EPIRB devices
• Receives AIS-SART devices
• Receives AIS-MOB devices
• Receives AIS-AtoN devices
• Receives transmissions from AIS base stations

The marine Automatic Identification System is used to transmit vessel position and identification information. Vessel position is derived from GPS data, while communication between AIS devices uses VHF digital transmissions. Received data may include vessel position, speed, course and identification information.

Vision RX data connections and interfaces

• USB interface for connection to a computer
• NMEA0183 high-speed output: 38400 baud
• NMEA0183 low-speed input: 4800 baud
• NMEA2000 interface, LEN=1
• NMEA2000 standard connector
• USB Type-A plug
• 12-way power input and NMEA0183 connection
• SO-239 VHF antenna connector

The 38400 baud NMEA0183 output is intended primarily for connection to a chart plotter. The 4800 baud NMEA0183 input can be used to connect other compatible sensors.

NMEA0183 multiplexing

The receiver includes a multiplexing function. Messages received through the low-speed NMEA0183 input are automatically transmitted through the high-speed NMEA0183 output. This allows a chart plotter with a single NMEA0183 port to receive AIS information and data from a connected sensor, such as a gyro-compass, at the same time.

NMEA2000 connection

The Vision RX can be connected to an NMEA2000 network using a suitable NMEA2000 network cable. When the chart plotter is connected to the same NMEA2000 network, received AIS targets can be displayed on the chart plotter.

USB connection

The receiver can be connected to a PC or Mac through its USB port. Received AIS messages can be displayed using compatible charting software. On Windows systems, the USB driver is installed automatically through Windows Update. A separate driver is typically not required when using macOS.

True Heading Vision RX power supply

• DC power supply: 9.6-31.2 V DC
• Suitable for 12 V or 24 V vessel power systems
• USB power supply supported
• Average power consumption: less than 1 W
• Current consumption: less than 200 mA at 12 V DC
• Recommended fuse: 3 A
• Red wire: positive power input
• Black wire: negative power input

The power supply should be connected through a suitable circuit breaker or 3 A fuse block. Crimped and soldered lugs are recommended for connecting the cables to the power source.

Connectors and wiring

• Brown wire: NMEA0183 Port 1 TX+, 38400 baud
• Blue wire: NMEA0183 Port 1 TX-, 38400 baud
• Purple wire: NMEA0183 Port 2 RX+, 4800 baud
• Yellow wire: NMEA0183 Port 2 RX-, 4800 baud
• Green wire: not used
• Orange wire: not used
• USB connector: PC or Mac connection
• PWR/DATA connector: power, NMEA0183 and USB connection

One end of the supplied accessory cable has a pre-moulded connector for the PWR/DATA socket on the receiver. The other end has eight colour-coded bare wires and a USB connector.

Connecting the VHF antenna

• Receiver antenna connector: SO-239
• Required antenna-side connector: PL-259
• Required antenna impedance: 50 ohm
• Compatible with a standard marine VHF antenna or AIS antenna
• An existing VHF antenna can be used with an antenna splitter

A suitable VHF antenna is required for operation. An antenna splitter can be used when one existing VHF antenna must be connected to both a VHF voice radio and the AIS receiver.

Vision RX mechanical and environmental specifications

• Dimensions: 140 x 100 x 42 mm
• Weight: 250 g, AIS receiver unit only
• Operating temperature: -25 C to +55 C
• Ingress protection rating: IPx7
• Can be mounted vertically or horizontally
• Below-deck installation is recommended
• Minimum compass safe distance: 0.5 m for 0.3 degree deviation
• UV-stable housing
• Four mounting holes

The unit has an IPx7 ingress protection rating, but extended exposure to spray or submersion is not recommended. It must not be installed in a flammable or hazardous atmosphere, such as an engine room or near fuel tanks. Sufficient space must be provided around the receiver for cable routing.

Indicators and operation

• Green power indicator LED
• Amber AIS reception indicator LED
• The green indicator illuminates when power is applied
• The amber indicator flashes when AIS messages are received

After installation and correct connection, the receiver is ready for operation. Information from vessels equipped with AIS transponders and located within radio range can be displayed on a compatible chart plotter or computer running suitable charting software.

Applications and compatibility

The dual NMEA0183 and NMEA2000 data connections allow the Vision RX to be used with compatible chart plotters and Electronic Chart Display Information Systems. Its average power consumption of less than 1 W also makes it suitable as a watch-keeping aid on small blue water cruising vessels.

The Vision RX is an aid to navigation. It is not a replacement for proper navigational judgement, vigilant human lookouts, RADAR or other navigation aids. Compatibility depends on the connected third-party systems recognising the receiver's standard AIS outputs.

True Heading Vision RX package contents

• True Heading Vision RX dual-channel AIS receiver
• 2 m power, data and USB cable
• 4 self-tapping mounting screws
• Quick start guide
• Warranty information
• Information flyer

A suitable marine VHF or AIS antenna is required for operation. The NMEA2000 network cable, optional antenna extension cable, antenna splitter, chart plotter and computer charting software are not listed as standard supplied accessories.

The receiver carries the CE mark and complies with the Radio Equipment Directive 2014/53/EU.