8-1
8. ALERTS
“Alert” is a generic name for a notice to any unusual or potentially dangerous situation
generated within the system. There are two types of alerts, warning and caution.
Warning: Conditions or situations which require immediate attention for precautionary
reasons.
Caution: Awareness of a condition which continues to require attention out of the or-
dinary consideration of the situation.
8.1 Overview
The GP-170 has eight types of alerts as follows:
ID Message Type Meaning
010
or
401010*
• D3D turned to 3D.
• D3D turned to 2D.
• D2D turned to 3D.
• D2D turned to 2D.
• S3D turned to 3D.
• S3D turned to 2D.
• S2D turned to 3D.
• S2D turned to 2D.
• D3D turned to "No Fix".
• D2D turned to "No Fix".
• S3D turned to "No Fix".
• S2D turned to "No Fix".
Abbreviated messages:
• D3D → 3D.
• D3D → 2D.
• D2D → 3D.
• D2D → 2D.
• S3D → 3D.
• S3D → 2D.
• S2D → 3D.
• S2D → 2D.
• D3D → "No Fix".
• D2D → "No Fix".
• S3D → "No Fix".
• S2D → "No Fix".
Caution The positioning system turns from
DGPS to GPS.
210 HDOP exceeded. Caution The value of HDOP (Horizontal Di-
lution of Precision) is 4 or above.
HDOP threshold being permanent-
ly set to 4.
211 No calculation of position.
Abbreviated messages:
No calculation of POSN.
Warning The signal from core is not received
for three seconds.
212 Loss of position. Warning No positioning data.