Autopilot Type NT921 MKII

  • Specifically designed for small professional vessel use (typically 11-20m LOA) the NT921 MKII Autopilot provides a powerful combination of steering system control and interface facilities based on an extremely intelligent Control Unit which is clearly marked and simple to operate.

    Navitron
  • Accordingly, the NT921 MKII offers Navitron steering expertise in a robust and compact package which includes the following special features:

    • Dual Channel Heading Inputs: NMEA 0183 Direct and Mag Sensor Coil
    • Built in Radio Navigator Interface for selectable (HI and LO) automatic track steering between waypoints.
    • Fully automatic stability compensation for variations in rudder speed.
    • Three Heading output Channels for Radar Stabilisation etc. (NMEA, Furuno & Step by Step)

    Standard Features:

    • Full P.I.D Intelligence,
    • Servo driven Heading Repeater (Standby mode),
    • Dual Course Setting and Steer on Lock on facility,
    • Full Automatic Permanent Helm,
    • Digital displays of Heading, Rudder Angle and Cross Track Error (CTE),
    • Operator variable control panel illumination,
    • 11-40Vdc Power Supply compatibility,
    • Solid State Output stages. (11-40Vdc/5A max),
    • Full range menu driven installation presets.
  • Straightforward operation is a key feature of the NT921 MKII thus operator controls are kept to a minimum and are clearly identified by control panel markings which are red backlit for night viewing via a variable intensity illumination control.

    A conventionally marked Course Selector permits simple course selection which is automatically corrected to maintain the vessel on a specified track when connected to a GPS or Track Plotter programmed with a track based on predetermined waypoints.

    Suitable for console or bracket mounting, the NT921 MKII Control Unit is intended for wheelhouse location and is supplied complete with Heading Sensor Coil and Rudder Reference Unit for installation to solenoid hydraulic systems (11-40Vdc/5A max).

    Optional Equipment:

    • Rudder Indicators,
    • Power Steer Controls,
    • Off Course Alarm,
    • Watch Alarm,
    • Universal Relay Box,
    • Analogue Steering Interface,
    • Dual Steering Interface,
    • Bowthruster Interface.

NT850 Main Steering System

  • All SOLAS/Class rated vessels are required to be fitted with Main and Backup Steering facilities and components which have been Approved and Certificated commensurate with relevant flag and Classification Society performance and reliability standards.

    Accordingly, all Main Steering System components designed & manufactured by Navitron Systems Ltd. have been fully Classification Society Approved (Germanischer Lloyd) and may be configured for complete Main Steering console configurations and/or stand alone component use as appropriate.

    Navitron Heading Data Interface types NT990 HDI & NT925 HDI are available for this purpose.

    Navitron
  • Whilst a typical Main Steering console might comprise Full Follow Up, Non Follow Up and Override Steering Controls etc. the final content can be chosen to reflect the complexity of the Steering System(s) involved (single or dual rudder, SOLAS or Non SOLAS etc.) thus a modular and cost effective concept of Steering Control Panel variants result.

    Type 1 - SOLAS compliant dual pump or dual rudder system.
    (Autopilot + FU & NFU Control Mode Select and dual pump or dual rudder System Select)

    Type 2 - SOLAS compliant dual rudder system with dual pumps per rudder.
    (Autopilot + FU & NFU Control Mode Select and Manual Override facility)

    Type 3 - SOLAS compliant as Type 2 with Heading Repeater but without Autopilot
    (FU & NFU Control Mode Select and Manual Override facility)

    Type 4 - SOLAS compliant for larger single or dual rudder vessel applications.
    (Autopilot + FU & NFU Control Mode Select with Manual Override facility, Heading Repeater and Rudder Angle Indicators)

  • This modular aspect also extends to associated electronic elements which may be required to complete Steering System Configuartions (Steering Amplifiers etc.) in addition to Heading Control (Autopilot) and Analogue Heading Indication (Gyro Repeaters).

    All NT850 electronic Main Steering System configurations are suitable for direct connection to nominal 24Vdc or 110/230/440Vac power supplies (derived from existing main steering gear Starter Boxes) via optional NT850 Power Supply Units.

    Fully comprehensive set up facilities are included to provide immediate compatibility with all Steering System types therefore standard Navitron NT850 Steering Amplifier outputs include bang/bang switchlines for simple solenoid control in addition to +/-10Vdc and 4-20mA signals for proportional valves etc.

Gyro/Mag Heading Repeaters Type NT880 AHR & NT990 AHR

  • Navitron Analogue Heading Repeater types NT880 AHR & NT990 AHR are Approved and Certificated by Germanischer Lloyd as fully compliant with all aspects of IEC 60945 and may be configured for single or multihead display of NMEA 0183 Heading Data received from proprietary transmission elements (Gyro, TMC systems etc.).

    In cases involving non NMEA data sources (proprietary Gyros etc. with step by step or synchro type outputs) an Approved Navitron Heading Data Interface may also be employed for conversion of step/synchro signals to NMEA Serial Data.

    Navitron Heading Data Interface types NT990 HDI & NT925 HDI are available for this purpose.

    Navitron
  • Both Repeater types are self aligning (no calibration required) thus both the main and inner cards will automatically align with NMEA 0183 data received.

    Ships head is simply read from a 150mm diameter (NT880 AHR) or 180mm dia (NT990 AHR) main rotating card which is marked in 1° increments with 5° and 10° divisions also defined. The smaller diameter inner card rotates at a rate which is 10 times faster than the main card to provide a clear indication of tenths of a degree. All 3 digit numbers (4.5 or 5.0mm height) are shown at 10° intervals and all scale markings are white on black card backgrounds.

    Variable intensity backlight illumination is controlled from a dimmer pot mounted on the instrument panel(s) or via an external dimmer, to illuminate all card legends in red or green (link installation selectable) for night viewing.

    Operational integrity is continuously monitored and both Repeater types provide front panel indications of Heading Data type (True or Mag) and failure status (if appropriate) involving Alignment, Data and Power failure malfunctions. The visual indications are accompanied by an audible alarm which may be silenced when acknowledged by Alarm key operation.

  • Suitable for 11 – 40Vdc operation, all NT880 AHR Repeater heads are fully interchangeable (no master or slave distinction).

    The NT990 AHR heads are also fully interchangeable and both types may be panel or bracket mounted.

    Bezel outline dimensions of 192 X 192mm (NT880 AHR) and 240 X 240mm (NT990 AHR) allow the units to be mounted in the appropriate DIN size panel cut outs if required.

    A single input is necessary (NMEA heading data in at 4K8 or 38K4 baud) for each Repeater type. Additionally, two power supply inputs (normal and backup) a remote Illumination Control input and a power failure alarm output facility are available with a total of 5 cable entry glands provided.

  • NT880 Dimensios
  • NT990 Dimensios

Digital (DHR) Heading Repeater NT920DHR / 2

  • The NT920DHR / 2 Digital Heading Repeater is Type Approved (National Certification by UK Notified Body QinetiQ) for Gyro Compass or THD (etc) Repeater use and is immediately compatible with NMEA 0183 heading data. It is equipped with an opto isolated input port for direct connection to proprietary senders (gyro's, GPS compasses etc.) which transmit one or more of the following sentence types.

    $XXHDT, $XXHDG, $XXHDM, $XXHCC, $HCHSC

    Navitron
  • Ruggedly engineered and suitable for bracket or console mounting in internal and external locations , the NT920DHR / 2 may be installed in single or multihead configurations as add on repeaters with proprietary equipment or to provide an independent system with Navitron equipment such as the NT925OCA / 1 Off Course Alarm. Standard features include a 3 or 4 digit 25mm LCD display of current heading optimised for night viewing by operator variable red backlight illumination.

    Compass Safe Distance - 0.4m

Analogue Heading Repeaters NT920 AHR (MKI & MKII)

  • Navitron Analogue Heading Repeaters type NT920AHR may be configured as single or multi head independent systems or as add on components to most Navitron autopilot types and Navitron Heading Data Interfaces to display NMEA 0183 heading data received from primary transmission sources of all kinds (Gyro Compass, GPS Antenna Compass, TMC systems etc.)

    Location Note: Standard production units supplied from Serial N° 931899 (June 2002) onwards are of splashproof construction via sealed aluminium case and bezel housings to permit mounting in external locations.

    Navitron
  • Simple to install featuring fully automatic self alignment and self test facilities, all NT920AHR heads are supplied for panel or foot bracket mounting in sheltered locations (enclosed bridge or wheelhouse etc.) unless constructed to latest build standards (see Location Note)

    Ships head is clearly read from a 120mm diameter rotating card marked in 1° increments with 5° and 10° divisions also defined. All 3 digit numbers (4mm height) are shown at 10° intervals and all scale markings are white on a black card background.

    Variable intensity backlight illumination is controlled from a dimmer pot mounted on the instrument bezel to illuminate all card legends in red or green (installation selectable) for night viewing.

  • Unaffected by steel enclosures, the NT920AHR is particularly suitable for emergency steering position use in tiller flats etc.

Heading / Speed Data Interfaces Type NT990HDI

  • BSH (Germany) type approved for AIS, ECDIS, Radar and Heading Repeater interfacing, the NT990HDI (Heading Data Interface) will convert virtually any Synchro or Step by Step heading input signal to heading data transmitted on 1 (NT990HDI/1) or 2 (NT990HDI/2) isolated NMEA 0183 output channels. The output channels may be independently set for IEC 61162/1 (4800 baud) or IEC 61162/2 (38400 baud).

    Navitron
  • A speed log giving 200 or 400 ppNm may also be connected to the NT990HDI to provide NMEA 0183 speed information to proprietary systems.

    All inputs to the NT990HDI are Opto-Isolated to eliminate common mode and loading problems.

    The NMEA 0183 output sentences may be set for heading only ($HEHDT), heading and Rate Of Turn ($HEROT), heading and speed ($VDVHW) or heading, rate of turn and speed.

    Heading information is permanently displayed on a 4-digit LED display with variable intensity for night viewing whilst built in alarm functions triggered by internal monitors warn of heading input or NMEA output failure.

    An internal power-monitoring relay provides a volt free normally open (N.O.) or normally closed (N.C.) contact to warn of power supply failure. Contact rating 1A@30Vdc

  • Suitable for 11-40Vdc power supply connection, the NT990HDI may be powered up via the unit mounted ON/OFF keypad or from a remote location via remote power up terminals also provided.

Heading / Speed Data Interfaces Type NT925HDI

  • BSH Type Approved for stand alone (independent system) use with azimuth tracking units of all kinds (radars, trackplotters, antenna alignment systems, nav computers etc.) and Wheelmark approved for use with Navitron NT921G/NT951G/NT990G and NT991G MK2 autopilot systems, the NT925HDI (Heading Data Interface) provides four types of simultaneous output data converted from virtually any synchro or step by step gyrocompass heading outputs.

    Navitron
  • In addition, NT925HDI units incorporating software version 2.0r and later, will accept 200 or 400 pulses per nautical mile from speed log systems and will provide NMEA output data in heading only, speed only or combined speed and heading formats as required by ECDIS and AIS Systems etc. Version 3.0 software and later also provides Rate of Turn (ROT) NMEA data outputs.

    On receipt of gyro heading signals, all four data types are simultaneously and continuously transmitted on the relevant output channels which are opto isolated to eliminate common mode complications.

    When speed input data is available (200 or 400 pp.nm) combined speed and heading data is also available from the NMEA output channels (VHW sentence)

    Gyro heading data is permanently displayed on the NT925HDI via a 4 digit LCD with variable red backlight illumination for night viewing and built in alarm functions warn of gyro input and / or NMEA output data failure.

    An internal power monitor relay provides a volt free normally open (NO) or normally closed (NC) contact to warn of power supply failure (contact ratings 0.5A @ 125Vac, 1A @ 30Vdc).

  • Suitable for 11 - 40Vdc power supply connection, the NT925HDI can be powered up directly via its panel mounted ON/OFF switch or from a remote location via remote power up terminals provided.

Heading / Speed Data Interfaces Type NT923HDI

  • Suitable for stand alone (independent system) use, the NT923HDI (Heading Data Interface) provides two channels of 10Hz NMEA 0183 heading output data and one Navitron serial output derived from a Navitron Heading Sensor Coil (HSC1 or HSC2) mounted above or below a good quality externally gymballed ships magnetic compass.

    Navitron
  • The magnetic information received from the compass via the Heading Sensor Coil can be electronically corrected for deviation during installation and the resultant heading permanently displayed and transmitted at a fixed 10Hz update rate in the following NMEA sentence types (from software version 2.0 onwards) : $HCHDT, $HCHDM.

    Both sentences include checksum and are continuously transmitted at 10Hz on both NMEA output channels. The output channels are electrically isolated from the Ships supply and opto isolated to eliminate receiving equipment common mode connection problems.

    Built in alarm functions triggered by internal monitors warn of magnetic data (input signal) and NMEA output data failure.

    An internal power monitor relay provides a volt free normally open (NO) or normally closed (NC) contact to warn of power supply failure (contact ratings 0.5A @ 125Vac, 1A @ 30Vdc).

    Suitable for 11 - 40Vdc power supply connection, the NT923HDI can be powered up directly via its panel mounted ON/OFF switch or from a remote location via remote power up terminals provided.

  • Suitable for 11 - 40Vdc power supply connection, the NT923HDI can be powered up directly via its panel mounted ON/OFF switch or from a remote location via remote power up terminals provided.

Heading / Speed Data Interfaces Type NT922HDI

  • The NT922HDI provides conversion functions from NMEA Heading data to 5Vp/p Step by Step and from single channel NMEA Heading data to dual channel opto isolated NMEA outputs which are independently selectable to provide both baud rate and update rate conversions.

    Navitron
  • The NT922HDI NMEA serial data outputs are available in two sentence types ($XXHDT or $XXHDG) which are derived and reliant upon the input data received.

    The outputs (opto isolated) can be connected to external "listeners" in RS422, RS232 and standard NMEA connection formats.

    The input signal applied to the NT922HDI can be of a single type NMEA only

  • Suitable for stand alone 11-40Vdc power supply operation, the NT922HDI can be used in buffered NMEA to step repeater applications etc. and the baud rate conversion function provides a simple solution to many interfacing requirements involving equipment from different systems operating at different baud rates.

Heading / Speed Data Interfaces Type NT921HDI

  • The NT921HDI is available in two forms to convert Sin/Cos Heading signals received from proprietary compasses / fluxgate devices etc. to standard NMEA heading data. The resultant serial data accords with IEC 61162/1 and IEC 61162/2 (as preferred) and can be used as a heading input to a Navitron Autopilot System or for inputs to other proprietary equipment such as radar (stabilisation) or ECDIS etc.

    Navitron
  • This is the simpler form of interface which can be connected within a Navitron Autopilot System and uses the regulated power supplies available from the Autopilot Control Unit as it's power source.

    The PIC processor intelligent NT921HDI then decodes applied Sin/Cos Heading signal and converts the input signal to NMEA 0183 serial output data which is installation selectable for 4800 or 38400 baud and update rates of 1Hz or 10Hz as required.

  • This is the stand alone version of the Sin/Cos to NMEA converter and is suitable for direct connection to 11-40Vdc vessel power supply as voltage regulation is included in the NT921HDI/2 (Type 2).

    The single channel NMEA 0183 Heading data output signal is opto isolated to eradicate common mode problems and provides installation selectable update rates of 1Hz, 10Hz or 20Hz dependent upon the output baud rate selected (4800 or 38400).

  • For Sin / Cos compass to NMEA data.

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