Raymarine DSM250, Owner'S Handbook Manual

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Chapter 1: Overview 1-5
Transducer
The DSM250 requires a transducer, mounted either thru-hull, in-
hull, or on the transom.
Transducers can measure water depth, and if so equipped, temper-
ature, distance traveled, and/or speed. It is important to position
your transducer correctly. For details on transducers, including
location and installation instructions, see document number
81196,
Transducers for Fishfinders Owner’s Handbook .
Note: If speed, temperature, or distance travelled are being input to
the display unit via SeaTalk, the SeaTalk value is displayed instead of
the value transmitted by the DSM250.
Sonar Mode Display Features
When connected to a display unit and switched to Sonar mode,
the following data can be viewed:
• Depth, speed, and temperature, if the transducer is so equipped
• Single or split frequency sonar display – 50 kHz, 200 kHz
• Display options – sonar window, zoom, bottom lock, and A-
Scope
• Horizontal and vertical half-screen windows to display additional
data. Position data requires GPS.
1.2 Sonar Mode Display
When you first switch the display unit into Sonar mode, the
scrolling bottom graph is displayed. This is a graphical represen-
tation of the echoes seen by the DSM250. As time passes, this dis-
play scrolls from right to left and becomes a record of the echoes
seen. A typical display is shown in
Figure 1-3 .
The images at the right hand side of the display are the most
recent echoes. Some echoes indicate fish, and others show the
bottom. It can also indicate bottom structures, such as a reef or
shipwreck. The upper and lower depth range limits are shown.
The sonar screen includes a status bar that displays transducer fre-
quency and indicates which auto settings are enabled (Gain, Color
Gain, Range, Zoom and Frequency), and alarm status (fish and
shallow/deep water depths).