Version:
09
Date:
January 28, 2011
Document: Sigma 120 Rev 09
Page 29 of 60
Date 1
e
release: April 15, 2003
4.
Operation
4.1
Potentiometer on/off/dim
This is a potentiometer with a switch that switches-on the device when turned
in the clockwise direction. With the device switched-on, the lighting can be
adjusted between 5 to 100% by turning this potentiometer further to the right.
If the lighting is increased to the maximum level, the lighting in the foil is
switched-off to increase the life of the lamp.
4.2
Potentiometer alarm depth
This potentiometer is used to set the alarm depth.
The alarm depth can be set between 0 and 4m.
4.3
Alarm depth info
Press this button to check the alarm depth setting. The indicator will then
switch over from the actual depth to the alarm depth setting. After ± 5
seconds, the indicator will again switch back to the actual depth.
The alarm LED will start blinking to indicate that the indicator is showing the
alarm depth. If the range 2 (3-40m) is selected, the indication will be
temporarily switched over to the 4m range.
4.4
Depth range
With this key, one can switch between the small range (0-4m) and the large
range (0-40m). If two transducers are connected, both of them will switch-
over. If SW1 is switch on, the Sigma 120 switch automatic to the right range.
4.5
Selection of the transducer
With this key, one can select between transducer 1 and transducer 2. If this key
is kept pressed-down, the unit will switch over to a transducer different to the
one that is currently active. The LED relating to the transducer will also light
up. If no secondary transducer is connected then there will be no indication.
The secondary transducer can only be selected when the display unit is
equipped with the correct software version.
4.6
Reset / Test key
Reset
When the alarm depth set is reached, the red alarm depth LED will light up,
and an acoustic alarm signal will be heard. The acoustic alarm signal can be
switched-off using the
key. The alarm depth LED will continue to be lighted.
If one of the two power supply sources fails, the power supply LED will light
up in red (if both the power supply sources are present, this LED will light up
in green) and an acoustic alarm signal will be sounded.
