Garmin GSD 21 - Manual (Page 11)

9 GSD 21 Sonar Module
I
NSTALLATION
I
NSTRUCTIONS
Blink Codes
When the unit is installed, it switches on when the display unit is powered on (or the GSD remote power line is pulled low, with power applied).
The two-color (Green/Red) LED on the GSD 21 indicates the current operational status of the module. Codes are:
Code Status
Green blinking, on for 1 second, off for 1/2 second (slow blink) GSD 21 is servicing one directly wired connection and the display
device is operating properly.
The user should see sonar data on the display unit.
Red blinking, on for 1 second, off for 1/2 second (slow blink) GSD 21 is powered on but is waiting to connect to a display device. In
this state, the GSD 21 does not transmit any sonar signals and is not
sending out any sonar information to display units. If a display unit is
connected and this code persists, check the wiring.
Solid Red (no blink) Software failure - Call Garmin Product Support. If the cause is a
software error, the display unit can show the error. Power must be
cycled to clear the error.
Red blinking, on for 1/10 second, off for 1/10 second
(very fast blink)
System alarm. The display device gives a message indicating the type
of failure. After the alarm condition is fixed, power must be cycled on
the GSD 21 to clear the alarm.