HEIDENHAIN ND 1300 VED and Crosshair Systems - Manual (Page 274)

254 QC-300 Series User’s Guide
VED screen
The VED screen contains fields for specifying edge
detection and auto-enter parameters, setting user per-
missions for zeroing axes on the video DRO and for
performing video magnification and camera skew cali-
brations.
Specifying minimum probed points
The number of points to be collected for a circle, arc or
line is specified by the user in the probe pop-up screen
discussed in Chapter 5: Probes. When the number of
points actually collected falls below the required percentage of the number specified in the probe pop-up
screen, a “Failed measurement” error message is displayed and the measurement is aborted. To specify the
required percentage of points, touch the Probe Points Requirement data field and enter the desired percent-
age using the number keys.
Specifying light settling time
When a lighting level is changed during the execution of a program, a settling time is included that allows
the new light level to become stable. To change this settling time, touch the Light Step Delay data field
and enter the new time in milliseconds using
the number keys.
Specifying contrast threshold
Screen contrast is a combination of the illumination difference between adjacent light and dark regions on
the screen and the sharpness of the transition from light to dark. Perfect contrast could be loosely described
as very light and very dark regions that meet at a very sharp transition. The contrast threshold is expressed
as a percentage of perfect contrast and defines the minimum contrast required for video edge detection.
The contrast threshold value can be specified by touching the contrast threshold data field and entering
a percentage, or by touching and sliding the
yellow arrow up or down the contrast bar on
the right side of the LCD.
NOTE
The contrast threshold cannot be changed on the LCD when Lock Contrast Threshold
is set to Yes on this screen as described later in this section.