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IV. LED Signals
The Device is equipped with a bi-color LED that indicate the Device’s state. Note, serial devices
are intended for use by one application at a time and when the device is used in one application, you cannot
use it in another application or send a command from the console (this is described in the next chapter)
or update the firmware.
LED signals during a firmware update are described in chapter IX.
Table 1. Signals during a normal operation
LED Signal
Device State
One 0.5 second signal when
USB cable is connected
Device is powered. RED signal indicates that “silent mode” is active
and Device can send data to PC only, GREEN that Device in normal mode
and can send data in both directions (see chapter V).
Two 0.5 second signals
within a 3 second period
Device is connected to PC, port is not opened by an application. First
signal is GREEN if data from NMEA 2000 are received during the
period, RED otherwise. Second signal is GREEN if no data transmitted or
received over USB, RED otherwise.
Four very rapid signals with
a period of 1.5 second
Port is opened by an application. First signal is GREEN if data was
received from NMEA 2000 during the period (otherwise RED). Second
is GREEN if nothing was transmitted to NMEA 2000 by the Device
during the period. Third is GREEN if data was transmitted to PC during
the period. 4th is GREEN if no data was received from PC during
the period.
Constant GREEN signal
Device can not send data to application more than 3 seconds (application
hangs), but port is still opened by application. Connection with
PC application detected by the state of DTR signal.
One-second GREEN signal
Operation mode command is received and accepted (see the next chapter
for details).
