Cognex In-Sight 1721, User Manual

Page: 38 / 156

Section 3: Configuring a Wafer ID Application In-Sight
®
1700 Series Wafer Reader
28
FIELD STRING
ENTRY
DEFINITION VALID CHARACTERS
(.) dot (.)
(-) dash (-)
space space space
NOTE All characters that are not predefined or entered in the Field Definition are treated as an
alphanumeric wildcard.
Example : The Field String entry for a SEMI M12 standard character string can be
**********CS (the default Field String setting). Any alphanumeric character is valid in the
first 10 Field String positions. But in the 11
th
position, only alpha characters A-H will be
considered during the read. And in the 12
th
position, only numeric characters 0-7 will be
considered.
Fielding Barcodes
When the selected Mark is a barcode, the Field String must be changed so that it is
appropriate for the selected barcode mark.
To determine the barcode field string length and mark type, count the number of strokes
in the barcode. Divide the number of strokes by 4 to determine the number of characters
in the string. The remainder can be used to determine the barcode mark type.
REMAINDER BARCODE MARK TYPE
0 Invalid mark type
1 ‘BC, IBM 412’
2 Invalid mark type
3 ‘BC, BC 412’
Example:
1 The barcode contains 29 strokes.
2 29 divided by 4 equals 7. Therefore, there are 7 characters in the string.
3 After dividing by 7, the remainder is 1. Therefore, the mark type is IBM 412.
Field Definition
Optionally, the Field Definition setting can be used to create user-defined entries for the
Field String if Mark specifies a character string or barcode. When included in the Field
String, these entries restrict the list of valid characters at the positions in which they are
inserted.
Multiple field definitions can be used, separated by a semicolon (;).
Characters listed for a Field Definition entry must be contained in the font or barcode.
For example: &=123 is valid, because 1, 2, and 3 are valid characters. However,
123=& is invalid because ‘&’ is not included in the standard Semifont or barcode
character sets.