Maretron M001101 - Manual (Page 11)

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Revision 1.0 Page 7
3.2 Configuring Operating Mode
The RAA100 operates in one of two modes: 1) NMEA 2000
®
Mode, or 2) NMEA 2000
®
/
Analog Gauge Mode. You configure or place the RAA100 into NMEA 2000
®
Mode when you
are connecting the RAA100 directly to the resistive rudder angle sender (see Figure 2) and you
are not using an analog gauge. In NMEA 2000
®
Mode, the RAA100 supplies an electrical
current to the resistive rudder angle sender and monitors the changing voltage as the rudder is
placed in full port, center, and full starboard positions. Whenever the RAA100 is used together
with an analog gauge, then you configure or place the RAA100 into NMEA 2000
®
/ Analog
Gauge Mode. In this mode, the analog gauge supplies the electrical current to the resistive
rudder angle sender while the RAA100 monitors the changing voltage. Placing the RAA100
into NMEA 2000
®
/ Analog Gauge Mode requires you to configure or program the RAA100 with
the analog gauge’s resistance, which is described in Section 3.2.1. You can configure or
program a RAA100 operating mode through a display product such as the Maretron DSM200.
Refer to the user’s manual for configuring the RAA100 as the manual provides detailed
instruction on configuration procedures.
3.2.1 Configuring Analog Gauge Resistance
If you are using the RAA100 in the NMEA 2000
®
/ Analog Gauge Mode, then two different
analog gauge resistances need to be measured and programmed into the RAA100. You will
need an ohmmeter to make the two resistive measurements, which are 1) the power terminal
to sensor terminal resistance measurement (see Section 3.2.1.1), and 2) the ground terminal
to sensor terminal resistance measurement (see Section 3.2.1.2). Once you have made these
measurements, you can enter the RAA100 gauge resistances through a display product such
as the Maretron DSM200. Refer to the user’s manual for configuring the RAA100 as the
manual provides detailed instruction on configuration procedures.
3.2.1.1 Power Terminal to Sensor Terminal Resistance Measurement
The first resistance measurement is between the power terminal and the sensor terminal found
on the back of the gauge. Before making the measurement, disconnect the power, ground, and
sensor wires from the gauge. Then, measure and record the resistance between the power
terminal and the sensor terminal (see Section 2.3.1.1 for help in determining which terminal is
which). Make sure to adjust the ohmmeter scale to give you whole numbers without over
ranging (sometimes indicated by blinking display or a 1 in the far left hand digit position). If you
see only numbers right of the decimal point, keep adjusting the scale down (usually the highest
ohm scale is indicated by a capital M for mega-ohms or 10
6
ohms while the next lower scale is
indicated with a capital K for kilo-ohms or 10
3
ohms). Typical resistance values between the
power terminal and the sensor terminal are between 100 and 200 ohms so you should be able
to use the 200-ohm scale.
3.2.1.2 Ground Terminal to Sensor Terminal Resistance Measurement
The second resistance measurement is between the ground terminal and the sensor terminal
found on the back of the gauge. Before making the measurement, disconnect the power,
ground, and sensor wires from the gauge. Then, measure and record the resistance between
the ground terminal and the sensor terminal (see Section 2.3.1.1 for help in determining which
terminal is which). Typical resistance values between the ground terminal and the sensor