When the "Configuration" tab is clicked and the "Z-Search" button is pressed, the panel is displayed in the bottom right of the Configuration page. This panel defines the parameters for searching for the Z height of a surface using the "Z-Contact Sensor".
The Z-Search is an option that can be selected for any Path. When enabled, at the start of the Path, GD samples the Z-Contact Sensor to locate the height of the work surface at the first Node position. The correction between the actual height and the Z height of the first Node is dynamically applied to all Nodes in the Path.
If a Path has Z-Search enable, at the start of the Path, the syringe tip will be controlled as follows:
- Moves to the "Approach" position above the first Node.
- Moves down in Z at the "Search speed" and "Search accel" traveling a maximum "Search distance".
- Monitors the "Probe digital signal" and stops when the signal becomes TRUE.
- Retracts the syringe at 25% of the "Search speed" until the "Probe digital signal" is FALSE. This permits a faster "Search speed" while still obtaining an accurate height reading.
- Computes the difference between the first Node's Z position and the detected Z position minus the "Backout gap distance".
- Moves to the first Node position and all subsequent Nodes in the Path applying the Z correction and the X/Y/Z offset defined in the Path Editing Page to all Nodes.
Normally, the Z offset specified in the Path Editing Page is utilized to move the entire Path up to the proper height above the work surface to correctly dispense the fluid.
Z-Search Settings |
Description |
Probe digital signal |
Defines the Digital I/O signal number for the contact probe. This signal becomes TRUE when the surface is detected. This defaults to 10039, which is the DIN signal normally connected to the Z-Contact Sensor. |
Search speed (% max) |
Defines the speed (as a percentage of the robot's maximum nominal speed) for the search motion. |
Search accel (% max) |
Defines the acceleration (as a percentage of the robot's maximum nominal acceleration) to be used during the search motion. |
Search distance (mm) |
Defines the maximum distance in mm that the robot is permitted to move during the search. If this distance is exceeded, the search will fail and will generate an error. |
Backout gap |
Defines the distance in mm between where the slide is fully extended and where the slide is retracted sufficiently to trigger the contact sensor. |
Save |
Saves the settings to the flash disk. |