EN 61023:2007 – Maritime navigation and radiocommunication equipment and systems – Marine speed and distance measuring equipment (SDME) – Performance requirements, methods of testing and required test results

4 Minimum performance requirements
4.1 General
a) (MSC.96(72)/A1 .1 /2) Devices to measure and indicate speed and distance are intended for general navigational and ship manoeuvring use. The minimum requirement is to provide information on the distance run and the forward speed of the ship through the water or over the ground. Additional information on ship’s motions other than in the forward axis may be provided. The equipment shall fully comply with this performance standard at forward speeds up to the maximum speed of the ship. Devices measuring speed and distance through the water shall meet the performance standard in water of depth greater than 3 m beneath the keel. Devices measuring speed and distance over the ground shall meet the performance standard in water of depth greater than 2 m beneath the keel. Radar plotting aids/track control equipment require a device capable of providing speed through the water in the fore-and-aft direction.
b) (MSC.96(72)/A1 .3) In addition to the general requirements in Resolution A.694(17) as detailed in IEC 60945, devices to indicate speed and distance shall comply with the minimum performance requirements of this standard.
c) Where SDME information is generated by one unit of equipment and is displayed on another unit, the combination of the two units shall be regarded as forming the SDME and shall be tested as an entity.
d) Any facility provided by the equipment which is additional to the minimum requirements of this standard shall be tested to ensure that its operation (and, as far as is reasonably practicable, its malfunction) does not degrade the performance of the equipment.
e) The system shall consist of a sensor and the necessary processing unit to convert the output signal of the sensor to speed and distance for display and for transmission to other equipment.
4.2 Methods of presentation
a) (MSC.96(72)/A2.1 ) Speed information may be presented in either analogue or digital form. Where a digital display is used, its incremental steps shall not exceed 0,1 knots. Analogue displays shall be graduated at least every 0,5 knots and be marked with figures at least every 5 knots. If the display can present the speed of the ship in other than the forward direction, the direction of movement shall be indicated unambiguously.
b) (MSC.96(72)/A2.2) Distance run information shall be presented in digital form. The display shall cover the range from 0 to not less than 9 999,9 nautical miles and the incremental steps shall not exceed 0,1 nautical miles. Where practicable, means shall be provided for resetting a read-out to zero.
c) (MSC.96(72)/A2.3) The display shall be easily readable by day and by night.
d) (MSC.96(72)/A2.4) Means shall be provided for transmitting measured speed and distance run information to other equipment fitted on board.
(i) (MSC.96(72)/A2.4.2) When the equipment is used for measuring forward speed, then the information may be transmitted using closing contacts and, if so, this shall be in the form of one contact closure each 0,005 nautical miles run. The minimum contact closure time or equivalent pulse width shall be 50 ms.
(ii) (MSC.96(72)/A2.4.1 ) The information on all speed and distance parameters, including direction, shall be transmitted in accordance with the relevant international marine interface standards.
The equipment shall support at least the sentences VBW and VLW to IEC 61 1 62-1 . e) (MSC.96(72)/A2.5) If equipment is capable of being operated in either the “speed through the water” or “speed over the ground” mode, mode selection and mode indication shall be provided.
EN 61023:2007 – Maritime navigation and radiocommunication equipment and systems – Marine speed and distance measuring equipment (SDME) – Performance requirements, methods of testing and required test results