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GBAS/SCAT-I Mode (Options R&S
EVSG-K4/-K5)
R&S
®
EVSF1000
138
User Manual 1178.6410.02 ─ 05
Example: Interpretation of a "fixed"-type element
The
fixed
-type element expects a certain number of bits to have a specific value. If
the incoming bitstream matches, the result value is
OK
, otherwise it is
NOK
.
The result of the interpretation on the R&S
EVSF1000 is a table similar to the exam-
ples in DO246, in this case:
Table 8-1: Output in Message view table
Data Content
Bits used
Value
Binary
Power stabilization
15
OK
000000000000000
Sync. and ambiguity resolution
48
OK
0100011111011111
1000110001110110
0000011110010000
All available element types are described in
Chapter 8.6.4, "Format Description of Ele-
Control elements
Each GBAS burst can contain one or more messages. The messages have different
message types with different content. The content of the same message type can
depend on certain parameters which are only known during runtime. Therefore, control
elements such as a case-dependent branch to a further XML file are supported.
Example: Case-dependent processing
This example shows how the parser is directed to different instructions, which are
stored in additional XML files, depending on the determined message type:
<Element>
<data_content>Message</data_content>
<data_content_short>MSG</data_content_short>
<type>link_sel</type>
<link_sel>MTI</link_sel>
<link_case>
<value>1</value>
<link>GbasMsgType1.xml</link>
</link_case>
<link_case>
<value>2</value>
<link>GbasMsgType2.xml</link>
</link_case>
<link_case>
<value>4</value>
<link>GbasMsgType4.xml</link>
</link_case>
</Element>
The additional XML files have the same format and supported elements. They can
branch to even more files, there is no limit to how deeply the files are nested.
Message XML Interface