Simrad AP27 Marine Instruments User Manual


 
Maintenance
20221586B 109
Decoding
The incoming signals are decoded according to a built in priority
table in the autopilot. Cross Track Error and bearing information
are taken from the NMEA messages with highest priority.
For all data items, one of the following codes will be displayed:
No data or no NMEA sentence containing the data
needed is available at the input port.
OK Valid data found
INV Message with invalid information.
FRM Message has format failure such as
a) Incorrect check sum
b) Wrong contents in datafield(s)
If data are missing or invalid, perform the following:
Check the NMEA signal monitor (see below)
Open the source select page in the User Setup menu and
check that data are available
Check the navigator setup and make sure it is transmitting
appropriate data.
Perform a NMEA Port Test (hardware) as per below.
Note ! The “WIND” reading is the apparent wind from the port (L) or
starboard (R). The “SPEED” reading is the speed through
water.