Poseidon SE7EN User Manual
Appendix 3 Page 103
HUD Light
The HUD incorporates a RED LED light (Figure 3-1a), designed to signal that there is a possible
problem (Red). Under normal diving conditions, the GREEN LED light (Figure 3-1b) is fading in
and out continuously when the unit is in closed-circuit and there is no alarm. The RED light will
periodically blink to serve as a reminder to the diver to monitor the Primary Display. Whenever
a problem has been detected by the system or when any of the dive parameters are not within
safe limits, the HUD light will flash continuously RED (and the vibrator will “blib” every 60
seconds). In either case, the purpose of the HUD light is to alert the diver to look at the primary
display for further information.
Audio alarm
One of the two alarm systems located in the battery module is the audio alarm. It emits a loud
staccato tone that alternates between two frequencies as a signal to abort the dive. Whenever
the audio alarm is triggered, the diver should immediately terminate the dive and commence a
safe ascent to the surface, while monitoring the Primary Display. The audio alarm will continue
to sound whenever the mouthpiece is not in the correct position, or when the diver fails to
ascend in an abort situation.
Buddy alert light
Also contained in the battery module is the buddy alert light. This consists of two separate
high-intensity red LED lights that flash whenever the HUD Light is flashing. The purpose of this
alarm is to alert other nearby divers of a potential problem.
Monitoring the M28 primary display
Most of the information concerning the status of the dive and the various system parameters
is communicated to the diver via the M28 Primary Display. It consists of a 2,8” TFT Color
display and provides the diver with important information concerning sensor readings, system
messages, decompression status, and other data during the course of the dive. It is extremely
important that all Poseidon SE7EN divers understand how to read the information contained in
the Primary Display, particularly concerning various alarm conditions.
Before even turning the Poseidon SE7EN electronics on, it is useful to understand the general
layout of the Primary Display, and the logic behind how the information is organized. The
display is arranged in different regions, each presenting different kinds of information. The
most important region is the upper-right corner of the screen (1 in the illustration), which
contains icons for alarm conditions. Under normal circumstances, this region should be blank.
The alarm condition icons (described in more detail below) are designed to symbolically repre-
sent the nature of the problem, and most of them will flash when activated. This should be the
first part of the screen that a diver should glance at when monitoring the Primary Display, as it
will be immediately obvious if there are any alarm conditions, and what they are.
The battery icon will reflect the lowest value of M28 battery or the SE7EN battery. If the M28 is
detached from the SE7EN it will only indicate the M28 battery value.
Figure 3-1B.
HUD with green LED on.
Figure 3-1A.
HUD with red LED on.
