QUICK REFERENCE GUIDE
ITI Twin rig operation
Purpose
This guide provides general information
on how to use the Simrad ITI and
its appropriate sensors in a twin rig
configuration.
The functionality described in this
document is only valid with ITI SW
version 5.30 and later.
Language
The menu language is set from the main
menu using this command sequence:
System setup → Language
Trawl setup
The mode is changed to Twin rig by the
following command sequence:
Main menu → System setup → Trawl
setup → Trawl gear → Dual.
In the Trawl setup menu, the values for
Trawl width, Spread1 and Spread2 should
be set to their actual values in order to
achieve correct graphical presentation.
In the same menu, the Offset value must
be changed if the clump will not be on
line between the doors. The intention is to
bring the blue clump value to zero when
the trawls are going correctly through
the water. An increase of the value will
apparently ”shorten” the middle warp.
The Filter is implemented to smoothe
the same blue clump value in the Normal
and Trawl eye modes.
The value for the Trawl height will be
set automatically if only height sensors
(no trawl eye) is used. If the trawl eye is
in use, alone or together with the Height
2 sensor, its value must be programmed
under the Trawl eye setup. Refer to the
Trawl eye manual.
Slant h(orizontal) view must be switched
on if you want the horizontal range to
the trawl to be presented in the upper
half of the trawl eye and in the normal
picture. This function requires an active
depth sensor on the trawl.If the Slant h.
view is switched off, or there is no depth
sensor on the trawl, the slant range will be
presented instead.
Active sensors
The sensors to be used on the trawl are
chosen using this command sequence:
Main menu → Active sensors
Sensors that are not in use, or have no
battery power, should be switched off in
order to maintain the desired the update
rate.
Example: A sensor setup for twin rig
would include the following sensors: Two
Spread sets, two Temp/Depth, Trawl eye
and Catch 1&2&3.
TRAWL SETUP
TRAWL WIDTH 30m
TRAWL HEIGHT 8m
TRAWL TYPE BOTTOM
TRAWL GEAR DUAL
SLANT H. VIEW OFF
SPREAD1 45m
SPREAD2 45m
OFFSET 0.0m
FILTER 0
ACTIVE SENSORS
TEMP-DEPTH 1:1
GRID OFF
HEIGHT OFF
HEIGHT2 1:1
SPREAD1 1:1
SPREAD2 1:1
TRAWL EYE 1:1
CATCH 1:3
CATCH AVAIL 1&2&3
TEMP-DEPTH CENTER
HEIGHT2 STARB
SPREAD1 PORT
SPREAD2 STARB
TRAWL EYE PORT
CATCH 1 PORT
CATCH 2 STARB
CATCH 3 STARB
All sensors must be fitted correctly to
the trawl. The Spread 1 & 2, Temp/Depth,
Trawl eye and Height 2 sensors must be
set to an update rate of 1:1. Choosing
Catch 1&2&3 in the same menu must
correspond to the actual sensors placed
on the trawl. The update rate of the Catch
sensors is then for example set to 1:3 for
update every third interrogaton lap. On
which trawl the different catch sensors
are fitted (port or starboard) are thereafter
set in the same menu. The location of
the Temp-Depth sensor is also chosen
here. The remaining sensors have fixed
locations.
Update rate
When the sensors are correctly set up,
they can be turned on using the following
command sequence:
Main menu → Rate → On
This sequence controls the complete
system’s update rate. With the rate set
to maximum, the update speed will only
depend on the number of sensors in
use. When the rate is switched off, all
transmitters in the system will be inactive.
RATE
MAX
0.5 MIN
1.0 MIN
1.5 MIN
OFF
857-165137 / Rev.A / February 2005