DESIGNER’S HANDBOOK 4189350049C EN
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11.13.3.4
Possibilities in a customized library
The DEIF standard heading library we have used as example is made for general purpose use and the room for
auto-selection of NMEA sources are therefore relative wide. In customized libraries it is possible to limit the auto
selection to specific hardware ports and sentences, but also change sentence priority so that it fits directly into the
customers system and so that auto source scanning will automatically find the correct NMEA sources without need
for manual setup via the NMEA menu.
11.13.3.5
Troubleshooting the NMEA auto scanning and selection
If you cannot find a given NMEA sentence in the list and you know it is active on one of the input ports, you can try
to run the auto scan function again. If it is still not showing up there can be different reasons why it is not detected
as source, some typical situations are:
•
The RX A and B wire is swopped around, especially if RX2 (RS485) is used since the A/B convention for
marking is opposite the RS422/NMEA way of marking inputs. So just swop the wires and run the scanning
again, it this wiring is correct the sentence will be detected.
•
Not so common problem is that the sentence format used by the transmitter device is not quite correct, if
the format is not according to the IEC standard or from a very old NMEA0183 standard, XDi will not accept
the sentence as valid.
•
In some cases a problem can also be that a given sentence does not contain the actual type of data, the
data field may be empty (,,) or data may be marked as invalid (typically status V = invalid and A = valid )
XDi has a strong service tool for NMEA, where you can check if a NMEA sentence is actually received on one of
the inputs or not. The NMEA monitor tool is available in the Service menu (see the separate chapter).
11.13.4 When is manual NMEA input selection necessary ?
It is necessary to scan the NMEA inputs again and make a manual setup:
•
if you move the data source to another input port.
•
if you change the transmitting unit (data source) to a new type with another talker ID.
•
If you change the transmitting unit to a unit with same talker but use another NMEA sentence to transmit
the data. For a given data type, XDi normally supports all relevant sentences from the IEC standard and
automatically selects the sentence that has the highest priority (see document: XDi supported NMEA
sentences).
•
or if you make several of the above changes at the same time.
11.13.4.1
Master reset to clear it all
If you lose the overview and you can’t find sources or make the correct setup manually, it may be a good idea to
start from scratch. To do that you must make a “Master reset” (button 1 and 3 at the same time in 5 sec.) to clear all
NMEA source lists and input selections and make a completely new setup.
It may be a good idea to make a master reset and start from the beginning:
•
I If you have made big changes in the NMEA installation
•
Has moved the XDi from one system to another
Master reset is the only way to completely clear the source selections and start over from scratch.
11.14 Manual input configuration
11.14.1 Adjust a wind sensor misalignment from a menu
If the wind sensor was incorrectly aligned when it was mounted in the mast top, it is easier to make an angle
correction in the XDi instead of climbing the mast again.
Enter the installation
menu and select “NMEA input setup” menu where you find this:
