User guide

9-2 Vision System9-2
The sections below are an overview of the hardware operation of the Pattern Recognition System. See
Figure 9-1 to locate parts.
Theory of Operation
The camera turns ON, the image is processed through the vision processor and is displayed on the
monitor. The camera generates a crosshairs over the image. The crosshairs is calibrated to the XY
location using a FmNT routine.
After calibration, the Dispensing Head, camera and light source are moved to a fiducial location on a part.
The crosshairs are centered on a fiducial by using the motion controls on the Control Panel or the position
controls in the Teach Window. The programmer then can opt to use either an edge fiducial or a model
fiducial. A fiducial has parameters, such as light level that can be adjusted using the vision system menu.
This menu also can define the maximum fiducial search area. To help relocate a fiducial, its image and
XY location are stored in the vision system memory.
During a production run, FmNT calls the vision system when a fiducial-find instruction is encountered in
the program. The vision system attempts to locate the pre-defined fiducial. The vision processor recalls
the fiducial location and moves the camera to a pre-defined search area. The vision processor adjusts the
light levels and parameters as defined. The processor then looks for an image in the defined area that
matches the defined fiducial image. When it finds a fiducial, the vision processor tests the image for a
match. The results of the test are sent to FmNT and a message is displayed indicating whether the fiducial
was found or not. Finally, the fiducial search instructions are automatically inserted into the dispensing
program.
Operation
When using FmNT, the parameters that control the search characteristics, camera control, and light level
are located in the vision system menus, accessed through the FmNT software. See the Fluidmove for
Windows NT User Guide or Online Help.
Adjustments for the Pattern Recognition System
In FmNT, see Online Help for controlling Pattern Recognition System features.
Vision System Troubleshooting
Operator-performed troubleshooting procedures are listed in Table 9-1. Some symptoms that appear to be
problems with the vision system may actually have other causes. Refer more difficult problems to an
Asymtek service technician.
Table 9-1 Pattern Recognition System Troubleshooting
Symptom Check/Correction
Dispensing program
freezes
Reboot the computer, but do not press [
Esc] or [Enter] while in a vision
processor menu.
Camera-to-needle offset
incorrect
If you moved the camera to refocus it, you must reestablish the camera-to-
needle offset. In FmNT, perform machine setup routine for your specific
application (See Fluidmove for Windows NT User Guide for details).