Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 94)

7–6 Configuration: Scanner Control, Primary Match Table, Discrete I/O
Publication 2755-833
Figure 7.2 Inter-scan timer
Direction of Travel
Field #1 Field #2
Scan Line
S
W
D D =
W =
S =
Distance traveled during Inter-Scan Timer.
Width of label.
Distance between start of field #1
field #2.
The label orientation must be such that distance D is
≤
S for the
scanner to scan all of Field #2. The line speed must be constant.
Set the Inter-Scan Timer to a value between the minimum and
maximum values to prevent additional decodes of Field #1, while
allowing all of Field #2 to be scanned.
To allow multiple reads of a single symbol for verification purposes,
set the Inter-Scan Timer to a value that is less than equation 1.
Capture Count
Field Type Options
Select/Edit
1 through 8, or V
2
Specifies the number of identical valid scans that must be decoded
before a read is considered valid. The default is 2, which means the
capture count is not satisfied until two sequential, identical, valid
scans are decoded. A capture count of 2 is appropriate for most
applications.
To specify a different capture count, select a value between 1 and 8,
or V. V (for Verify) requires that each symbol in a bar code must
match an entry in the primary match code table to produce a valid
read.
The “V” capture count is useful in high speed verification
applications, where the value of the symbol is known. By loading the
expected value into a match code table, the decoder only needs to
acquire one valid scan matching the expected values to produce a
valid read.