Hardware manual

Grid Statistics Impact Reference Guide
Datalogic Automation Inc. 3-220
Grid Statistics
In the Specialized Drawer
The Grid Statistics tool provides extensive statistics about a series of points in a grid pattern. This tool can
be used analyze components such as contacts on electrical connectors, Ball Grid Array (BGA) ball spacing,
or other components where a grid of found points must be compared to an ideal list.
This Grid Statistics tool matches an Ideal Points list and an Actual Points list within a given set of toler-
ances. The point lists are both assumed to be relative to the same origin, and MUST be in the same order, i.e.
lowest X coordinate to highest X, lowest Y to highest Y (relative to the tool origin).
The Grid Statistics tool is similar to the Point Match tool, with several significant differences:
• The Grid Statistics tool requires that the Ideal Grid Points list and Actual Points list be ordered in the
same sequential order, which must be from lowest X to highest X, lowest Y to highest Y (relative to
the tool origin).
• The Grid Statistics tool always performs a Best Fit operation on the Ideal Grid Points list relative to
the Actual Points list. This is done to correct for locating errors which will minimize the errors that
would be associated with incorrectly referencing the Actual Points data to the Ideal Points data.
• The Point Match tool will run noticeably faster than the Grid Statistics tool for large point lists. The
difference in execution time is less noticeable on point lists less than 100 points in length.
Input Name What it is
Input Image Linked Image
Tool Origin The tool’s origin relative to the entire image space
Ideal Grid Points A point list representing an ideal part that is used as a template for com-
parison. The Ideal points MUST be presented in the sequence left to
right, top to bottom.
Actual Points A point list taken from a test part that is used to determine whether the
part is defective. This point list MUST be in the same order relative to the
Ideal point list (i.e. left to right, top to bottom).
Pitch Calculation
Method
Pitch to Next Row/Column: this specifically addresses "staggered" or
"hexagonal" grids. Also, The last row and column have a pitch calculated
back to the previous row or column, so that every point has x and y pitch
values.
Pitch to Next Point: the pitch is calculated to the point to the right, for X,
and the point below, for Y. This will fit a line to each row and column and
calculate the pitch as the distance from the point to the next row or col-
umn, even if the next row or column is staggered.
This option works best on uniform point grids that have a constant pitch
in X and Y across the entire grid.
Minimum X Pitch The minimum x-coordinate distance allowed between consecutive points
or rows
Minimum Y Pitch The minimum y-coordinate distance allowed between points or rows