1. Introduction
1.1 The EGC equipment to be used in the GMDSS should comply with the
general requirements set out in the annex to Assembly resolution A.694(17); relevant
IEC standards (IEC 61097-4 and IEC 60945) and the following minimum performance
requirements.
1.2 The equipment should be capable of producing a printed copy of
received information. Received EGC messages may be stored for later printing with an
indication to the operator that the message has been received, except for the vital
messages referred to in paragraph 3.2 which should be printed out upon receipt.
1.3 The EGC installation may be either separate or combined with
other installations.1
2. Technical requirements
The equipment should be type-approved by Inmarsat and should comply with the
environmental conditions and electromagnetic compatibility requirements specified in
IEC 60945.
3. Operation
3.1 The equipment should provide a visual indication that the ship's
position has not been updated during the last 12 h. It should only be possible to
reset this indication by revalidating the ship's position.
3.2 Means should be provided to enter the ship's position and
current and planned NAVAREA/METAREA codes manually so that area group calls can be
received. Means should also be provided to enter current and planned coastal warning
service coverage areas and different classes of messages. Optionally, the ship's
position, as determined by the navigational equipment, may be entered automatically
and the NAVAREA/METAREA code automatically derived therefrom.
3.3 Provision should be made for a specific aural alarm and visual
indication at the position from which the ship is normally navigated, to indicate
receipt of a distress or urgency priority EGC message. It should not be possible to
disable this alarm and it should only be possible to reset it manually and only from
the position where the message is displayed or printed.
3.4 The equipment should indicate when it is not correctly tuned or
synchronized to the EGC carrier.
3.5 Any message should be printed regardless of the character error
rate of its reception. The equipment should print a low line mark if a character is
received corrupted.
3.6 Acceptance or rejection of service
codes2 should be under the operator's control except
that equipment should always receive navigational warnings, meteorological warnings
and forecasts, search and rescue information and shore-to-ship distress alerts, which
are directed to a fixed or absolute geographical area within which the ship is
operating.
3.7 Means should be provided to prevent the re-printing of a message
once it has been received without error.
3.8 The printing device should be capable of printing at least the
standard International Alphabet Number 5 (IA5) character set. Other character sets are
optionally used according to ISO 20223 standards or CCITT
Recommendation T.61.
3.9 The printing device should be able to print at least 40
characters per line.
3.10 The signal processor and printing device should ensure that if
a word cannot be accommodated in full on one line, it should be transferred to the
next line. The printing device should automatically feed five lines after completing
the printed messages.
3.11 A local audible alarm should be sounded to give advanced
warning of the printing device "paper low" condition. It should not be possible to
confuse the sound of the "paper low" alarm with that of the distress or urgency alarm
caused by the reception of a distress or urgency priority message.
4 Sources of energy
4.1 The EGC equipment should normally be powered from the ship's
main source of electrical energy. In addition, it should be possible to operate the
EGC equipment, and all other equipment necessary for its normal functioning, from an
alternative source of energy.
4.2 Changing from one source of supply to another, or any
interruption of up to 60 seconds' duration of the supply of electrical energy, should
not require the equipment to be manually re-initialized and should not result in loss
of received messages stored in the memory.
5. Antenna siting
5.1 Where an omni-directional antenna is used, it is desirable that
the antenna be sited in such a position that no obstacle likely to degrade
significantly the performance of the equipment appears in the fore and aft directions
down to -5° and in the port and starboard directions down to -15°.
5.2 Where a stabilized directive antenna is used, it is desirable
that the antenna be sited in such a position that no obstacle likely to degrade
significantly the performance of the equipment appears in any azimuth down to -5°.
5.3 For omni-directional antennas, objects, especially those within
1 m of the antenna, which cause a shadow sector of greater than 2°, are likely to
degrade significantly the performance of the equipment.
5.4 For directive antennas, objects, especially those within 10 m of
the antenna, which cause a shadow sector of greater than 6°, are likely to degrade
significantly the performance of the equipment.
1Elements of other installations, e.g., the antenna, low noise amplifier and
down-converter of the ship earth station, may be shared for the reception of EGC
messages.2The meaning of the service codes is in accordance with the Recommendation ITU-R
M.540-2 1990, Operational and technical characteristics for an automated
direct-printing telegraph system for promulgation of navigational and meteorological
warnings and urgent information to ships.
Note:
ISO 2022, "Information technology – Character code structure and extension
techniques" standards.
3Note: ISO 2022, "Information technology – Character code
structure and extension techniques" standards.