Calculating Number Of Captures In A Rapid Capture Application - Microscan Quadrus EZ Reader User Manual

Capture Mode

Calculating Number of Captures in a Rapid Capture Application

1. First calculate the distance between multiple captures.
For multiple captures in Rapid Capture
mode, you can calculate the distance
between successive symbols by multiplying
the line speed by the capture time.
For CCD:
TRAVEL DISTANCE = Line Speed X 15mS
For CMOS:
TRAVEL DISTANCE = Line Speed X 30mS
Capture time is a fixed "overhead" that
includes the time of capture and transfer of
the image.
Note: For Dual Camera operations, add 33 mS to the overhead time for the first
external capture.
Example:
A symbol moving at 10 ips (inches per second) past a CCD reader travels 0.010"/mS
* 15mS = 0.15 inches between captures.
2. Next calculate number of captures.
Once the travel time is known, you can
easily calculate the number of captures
you can expect to occur inside a FOV by
subtracting the symbol size from the FOV
and dividing the result by the travel time.
NUMBER OF CAPTURES =
(FOV–Symbol Size)/Travel Distance
Following up on the example from Step 1:
0.78" – 0.4"/0.15" = 2.5 captures
If a required number of captures has been determined, you can also work the formula
backwards and determine the minimum FOV by:
FOV = (Number Of Captures * Travel Time) + Symbol Size
3-20
Distance traveled
between captures
0.78 inches FOV
0.4 inches
Symbol
Size
Quadrus EZ Reader User's Manual