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When you define the "Input Data Record Structure" in
the Wedge, you first define the events that determine the
start and the end of each data record. You then define how
you want the Wedge to parse each data record by selecting
a "Record Structure". You can have it parse your
data records based on either the positions of delimiter characters
within each record or by byte position in the record. The
Wedge always stops reading in data when it encounters the
specific "End Of Record Event" that you specify.
If you define more data fields than are actually present
in the data record then the remaining fields will be left
empty. You could take advantage of additional empty data
fields by using them to perform calculations on previous
data fields using a "Math Expression" in the empty
fields. For example suppose that you had a device that transmitted
a pair of numbers, X1 and X2, in the following comma delimited
format with a carriage return at the end of the data record:
X1,X2<Cr>
Suppose also that you wanted to pass these two numbers to
another program along with the difference between the two
numbers. To do this, you could define the input data record
structure by specifying the End Of Record Event as "Carriage
Return or CrLf Received" and then specifying the "Record
Structure" as "Multiple Delimited Data Fields" with
a comma as the delimiter and specifying three for
the maximum number of data fields. The actual data has only
two data fields before the carriage return so by specifying
three for the maximum number of fields, you will end up with
a third empty data field in the Wedge. For each field that
you define in the Wedge, you can also define a Math Expression
to be applied to the field. Math expressions in the Wedge
can contain references to previous data fields by using the "Field(n)" expression.
If you specified "Field(2) - Field(1)" for the
math expression for Field(3) (the empty field), then you
would end up with the difference between the two numbers
X1 and X2 in Field(3) in the Wedge.
More Cool Wedge Tricks
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