Wärtsilä SATLOG SLS 4120

The Speed Log System Wärtsilä SATLOG SLS 4120 measures Speed Over Ground (SOG), referenced to the ship’s axes, by using the input from a gyro compass. With a precision of greater than 0.2 knots or 2 % of speed. This accuracy is compliant with the IMO performance standard for Speed and Distance Measuring Devices (SDME) IEC 61023 and allows the Wärtsilä SATLOG SLS 4120 to be used as a speed log for ground stabilising applications or docking manoeuvres. Interfaces between the Display Unit, Electronic Unit and DGPS Sensor comply with IEC 61162.

Together with an EM-Log or other log sensor measuring the Speed Through Water (STW), the Wärtsilä SATLOG SLS 4120 becomes a central display for speed related information such as Speed Through Water and Speed Over Ground, as well as distances travelled.

    • Worldwide precise speed determination without differential signals
    • High adaptive double-end ferry mode
    • Supporting of docking manoeuvres by calculating also the rate of turn and transversal speed at stern by interfacing a gyro compass
    • Measurement of Speed Over Ground in the longitudinal and transversal ship direction
    • Standard speed accuracy of 0.2 knots
    • Speed accuracy of 0.1 knots in differential mode
    • Multitrack Differential Beacon Receiver
    • Comfortable configuration, maintenance andupdate of the SLS 4120 via the integrated web interface using a web browser
    • Ready for remote maintenance due to the Ethernet interface
    • Integrated 24V DC power supply for external components

    The SLS 4120 is a system for the calculation and visualisation of longitudinal and transversal speed over ground, distance travelled relative to the ground and consists of four components: the Electronic Unit, the Display Unit, the DGPS sensor and the DGPS antenna.

    Display Unit
    The Display Unit is optimised for the intended purpose and consists of several numerical and alphanumerical LED segment displays. 6 keys are available for user input as well as a buzzer for audible warnings. The communication between Display Unit and Electronic Unit is established via a serial interface compliant with IEC 611612-1. Normally optimised for console mounting, the Display Unit is sized to the international 144 mm x 144 mm standard. Furthermore a ruggedised housing is available. Display Unit power supply is 24 V DC.

    Electronic Unit
    The Electronic Unit offers 8 serial interfaces (compliant with IEC 61162-1 and 61162-2) providing information from the DGPS sensor and Gyro Compass as well as a Speed Through Water log to send the calculated speed information to the Display Unit. 4 digital relays and 1 digital input to handle different alarm types are available. Additionally the Electronic Unit is equipped with an Ethernet interface for configuration purposes. The Electronic Unit is supplied with power via its 24 V DC input which also distributes power to the connected components.

    DGPS Sensor and Antenna
    A common reception of satellite and differential signals are achieved via an all- weather DGPS antenna attached to the DGPS sensor via a single antenna cable using TNC connectors. The DGPS sensor is a high-precision GPS receiver with a dual channel beacon receiver for reception of IALA beacon DGPS corrections. The unit performs continuous RAIM calculations, thus enhancing the integrity of position data and attaches to the Electronic Unit for calculating the speed information.

    Technical data
    DGPS performance
    GPS receiver 12 channel L1, C/A code with carrier phase smoothing
    Update rate 5 Hz
    Position accuracy GPS: 5 m; DGPS: 1m (2d RMS) typical
    Cold start 1 min typical
    DGPS beacon receiver Dual receiver with automatic tuning
    Frequency 283.5 to 325.0 kHz
    MSK Bit Rates 50, 100 and 200 bps
    Cold start < 1 min typical
    Reacquisition < 2 seconds typical
    Sensitivity 2.5 μV/m for 6 dB SNR at 200 bps
    Speed accuracy
    GPS-only mode Complies with IMO Res. A.824 and IEC 61023 / 0,2 kn or 2 % whichever is greater
    DGPS mode 0,1 kn or 1% whichever is greater
    Serial ports 8 serial interfaces compliant with IEC 61162-1:
    - 1 port to be used as Display interface
    - 1 port to be used as DGPS sensor interface
    - 1 port to be used as Gyro interface
    - 1 port optionally to be used as STW-log interface
    Power interface 4 24V DC power supply (max. 1 A) interface for connected equipment
    Digital I/Os 4 alarm relays:
    - 2 programmable speed alarm (for rudder system, stabilizers or other applications)
    - 1 power failure alarm
    - 1 system failure alarm
    - 1 digital input
    Ethernet 1 Ethernet 100 Mbit (RJ45)
    Supply voltage, dimensions and weight
    Display Unit
    Supply voltage 24 V DC (supplied from Electronic Unit)
    Dimensions 144 mm x 144 mm x 53 mm
    Weight 590 g
    Electronic Unit
    Supply voltage 24 V DC (+30% / -10%)
    Dimensions 406,5 mm x 165,43 mm x 42,25 mm
    Weight 1900 g
    DGPS Sensor
    Supply voltage 24 V DC (supplied from Electronic Unit)
    Dimensions 135 mm x 130 mm x 40 mm
    Weight 490 g
    DGPS Antenna
    Dimensions 130 mm x 130 mm x 80 mm
    Weight 450 g
    Compliance with the following standards
    IEC 60945 General requirements
    IMO Resolution A.694
    IEC 61162-1 Digital interfaces- Part 1
    IEC 61162-2 Digital interfaces- Part 2
    IMO Resolution MSC 96
    IEC 61023 Marine speed and distance measuring equipment (SDME)
    IMO Resolution A.824
    IEC 62288
    IMO Resolution MSC 191
    Type approvals
    Requirements according to Marine Equipment Directive (MED), USCG

    Wärtsilä SAM4642 and Wärtsilä SATLOG SLS 4120 combination to fulfill carriage requirements

    SOLAS adoption for carriage requirement resolution MSC.334(90) states that all ships constructed on or after 1 July 2014 and ≥ 50.000 GT are required to carry a separate speed log for measuring speed over the ground(SOG) additional to the speed through water log (STW).

    The Wärtsilä SAM4642 EM-Log (STW) and Wärtsilä SATLOG SLS 4120 (SOG) combination is a cost-efficient and type approved solution to fulfill these requirements.

    • Only one underwater transducer for the EM-Log is needed to determine the speed through water, the speed over ground is calculated using solely the GPS component.
    • Compared to conventional log systems our SATLOG SLS 4120 provides you with speed over ground information independent of water depth.

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