Simrad GN33

February 4, 2005 Alert 1-05
Washington, DC
GPS Receiver Manually-Entered Position Offsets May Cause Safety Hazard when Interconnected to Navigation Devices
It has come to the attention of the U.S. Coast Guard that certain Global Positioning System (GPS) receivers do not provide a proper indication to other connected equipment when manually-entered position offsets are entered into the GPS receiver. Even a small offset could result in danger of collision or other navigation safety hazard when the receiver is interconnected to devices such as an automatic identification system (AIS), Electronic Chart Display and Information System (ECDIS), integrated navigation systems (INS) or track control system (TCS).
The problem is caused by an error in the NMEA 0183/IEC 61162 data interface Datum Reference
(“DTM”) “local datum” field. Navigation systems interconnected to the GPS receiver use this field to
determine whether the position received is referenced to World Geodetic System 84 (WGS84) or
something different. AIS equipment, for example, disregards external position information for reasons
of safety if the “local datum” field does not indicate WGS84. As a result, equipment that is interfaced
to GPS receivers having this problem would act as if the position were referenced to the WGS84
datum, when in fact the position differs from the WGS84 datum by the manual offsets entered by the
vessel’s crew or captain.
The problem can be identified if own ship position displayed on an AIS changes in proportion to
manually-entered offsets entered into the GPS receiver interconnected to the AIS. The GPS is
operating correctly in such a situation if the AIS reverts to its integral GPS and disregards the
manually-entered offsets sent from the externally-connected GPS.

GPS Receivers identified having this problem:
Furuno GP80
Furuno GP90
Mariners having these receivers are advised to either take steps to ensure that the manually-offset
feature is never and can never be used, or to disconnect these receivers from the AIS, ECDIS, INS,
TCS or other navigation or communications system.
Technical questions relating to this alert may be addressed to Mr. Lee Luft at (860) 441-2685 or
LLuft@rdc.uscg.mil.
This material is provided for informational purpose only and does not relieve any existing domestic or
international safety, operational or material requirement.


This information is to inform you that the Simrad
GN33 has been tested and approved to meet the
requirements regarding change of datum as
described in IEC 61162. An immediate double
check has been conducted and Simrad can confirm
that the GN33 does not have the described
problem.
The GN33 sends out a DTM sentence, which
cannot be switched off, and therefore the correct
information concerning manually entered position
offset or selected datum are always available for
connected equipment e.g. AIS, ECDIS and radar.

Frank

GC80/85 Gyro compasses

New software has now been released to improve Simrad’s GC80/85 Gyro compasses.

The following functions have been implemented:

- Pendulum function.This enables the gyro to make a 180° heading shift by closing a potentialfree contact.

- HDG with HDT as first priority when reading external heading sensor

- Two decimals in Rate of Turn signal (NMEA):$--ROT,-xxx.xx,A*hh

All gyro compasses shipped after 07.02.05 include this new software, identified by code BA for Master compasses and Control units.
Note that the identification tag is only put on the cardboard boxes and not on the units. The present software will however be shown in the control unit display during turn-on of the gyro.
Do also note that Master compasses and Control units must have identical codes. Units with code AA and code BA must not be mixed!

For GC80/85 Sensitive element (part no. 44174027/44170728) and Power Supply unit (part no 27101724) the code will remain as before: AA.


The following software codes are used:
Part no
Unit
Sw code
27101674
GC80 Master compass
V.1.R.03
27101682
GC85 Master compass
27101690
Compact control unit
V1.R.04
27101708
Expanded control unit
27101716
Dual control unit

Spareparts affected with this software change are:
44142313 GC80/85 MCC pcb assy (Master Compass)
44142354 GC80/85 ICIF pcb assy (Compact Control Unit)
44142420 GC80/85 SCC pcb assy (Expanded and Dual Control Unit)
44142453 GC80/85 SCOIF pcb assy (Dual Control Unit)
44142495 GC80/85 PCC pcb assy (Dual Control Unit)

Pcb’s with rev.AA have no software label.
Pcb’s with rev.BA are marked with the new software codes as per. above.
Important:When ordering spareparts, please note the current rev. of Master Compass and Control Unit and clearly specify the software code required.

NEW LUBRICANT OIL
A new and better lubricant oil for use on the compass’s slip rings is now available. The name of the lubricant is "Applube", and it is ordered on part no. 27102128 (20ml.)


Frank

Simrad News Bulletin

CX34/44/54 NavStation and
CP31/CX33 Chartplotter


Radar Power Supply
Radar scanners must be ordered with matching
power supply. The new CX NavStations do not
include power supply for the radar scanners. The
RS4050 is still required for the RB714/715/716
scanners and the RS4052 is required for the
RB717/718 scanners.

MAX cartography
The new navigation products CX NavStation and
CX/CP Chartplotter are designed to operate with
the new MAX as well as the existing NT+
C-Cards.
However, do not use MAX and NT+ at the same
time. They do not mix.
Chartplotters and combination products prior to
CX NavStation and CX/CP31 Chartplotter do not
support the new MAX cartography.

GPS antenna
Due to unforeseen delay of the new GPS-5
antenna, the new CX and CP units will be
delivered with the well-known GPS-4 antenna.
Simrad expect to have the new GPS-5 antenna some
time in April 2005.

Bonded and not bonded displays
CP31 is not bonded, but comes with a marine
acrylic lens, which minimizes condensation i.e.
certain conditions may cause temporary
condensation built-up on the inner side of the
display.
CX/DS/EQ33 and CX/DS34 all have the new
bonded display technology, which improves
readability – SunView – and totally eliminates
condensation.
CX/DS/EQ44/SV and 54 are not bonded.
However, Simrad plan to introduce bonding on the 44
TFT model as soon as possible. The best estimate at
present is some time in March 2005.

New power connector
At the SWWC Simrad presented an idea for a new
power/NMEA connector for the 6” series.
Unfortunately, due to technical complexity regarding
watertightness and pull strength, it has not
been possible to complete the connector in time
for this season. Simrad will continue to work on a
solution, but do not expect to have an introduction
for the 2005 season.

IS12 Instruments SimNet info

Background Information
When performing a SimNet ‘DataSource’ set-up
procedure it is possible that some IS12 instruments
manufactured during the early part of 2004 can show
the incorrect manufacturers name.

Symptoms
On a SimNet product with a medium or large display
(like CExx, APxx or CPxx), when you access the
installation/SimNet set-up display and study the
detailed information for a particular product on the
SimNet bus, the Manufacturer name will be presented
as ‘Thomas G Faria’ and not ‘Simrad’.
Investigation
An investigation has revealed that IS12 products with
full SimNet software invoiced between 29-Mar-04
and 02-Jul-04 will exhibit the above symptoms.

Effect
The incorrect name has minimal impact on the
functionality of the instruments. In systems with IS12
Instruments that exhibit this behaviour, an error
message (‘Err’) could appear for a short time on a
repeater such as Mega, Data, Compass or Wind. The
error message is displayed for two seconds and then
the repeater returns to normal functioning.

Solution
By simply plugging in an IS12 Remote Control (full
SimNet version, serial number UD1001 onwards)
into the network the manufacturer name will be
instantly rectified and any affected units will function
correctly.

Frank

Simrad Egersund Obsolete Spares

Gyro Repeaters

Simrad has during the last couple of years undergone several changes and improvements to their gyro repeaters. Due to difficulties in providing support for old models, we are sorry to inform that the following products will, as of today, be out of our spare parts pricelist:
27102904 Exch: RDR74 Digital Repeater
27103092 Exch: RDR75 Digital Repeater
27102847 Exch: RSR77 Steering Repeater
27103019 Exch: RSR68 Steering Repeater
Following repeaters will be replaced by the new models:
27103100 Exch: DR75 Digital Repeater
44175768 Exch: AR77 Analog Repater
27103191 Exch: AR68 Analog Repater

Regards Frank