2. Tuning the signal quality
When the signal strength is tuned, check the second LED’s signal. It will be GREEN,
if the quality of the signal is good. If the signal is RED, try removing one or two turns
(the first signal must remain GREEN, we assume that the signal is overamplified, as at
Figure 1.B), or, conversely, try to add one more turn (assuming that signal is amplified
not enough amplified, despite the first signal being GREEN). The general rule is to
have the smallest possible number of turns enough to keep first two signals GREEN
at idle revolutions.
3. Adjust the RPM divider and the algorithm
When the quality of the signal is tuned, you should adjust the RPM divider if required.
Note, that the NMEA 2000 Standard limits an engine revolution at 16384. Even if you
need the divider 8, at idle speed (600-900 RPM) revolutions will be visible at MFD and
will be 8 times higher (4800-7200 RPM). But to complete the installation, you need to
test it at full speed, because at full speed noise can become higher (and you may need
to change the route of Device’s wire).
For most modern 2-stroke twin-cylinder outboard motors a divider of 0.5 is required.
Classic 2-stroke engines and 4-stroke engines with CDI need a divider of 1 (factory
setting). Classic 4-stroke engines with an ignition distributor need a divider of 2.
The Device has four built-in algorithms of signal processing. The first algorithm
(factory default) is optimized to count up to 15000 pulses per minute and cut high-
frequency noise from the signal. It is well suited for RPM dividers 0.5-2. The second
algorithm counts up to 70000 pulses per minute and must be manually selected if you
are using a divider of 3 or higher. Algorithms 3 and 4 are experimental and can be
changed in future versions.
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