CAENels BEST User Manual page 28

BEST Local GUI
The control section is composed by a "Heartbeat" indicator (
the feedback status. There are four possible statuses:
• Feedback OFF – the feedback loop is disabled and on output there are only
user defined offsets (user defined offset is the PID offset field in the PID
configuration panel, see section 4.1.3). This mode can be used to manually
position the beam in a desired location by changing the PID offset field.
• Feedback ON – the feedback is enabled and the output is calculated by the
PID algorithm (see
• Fault: Out of ROC – this is an error message which means that the beam
position has moved outside the user defined ROC; as a consequence the
feedback is automatically stopped. Before starting again the feedback with the
"Enable feedback" button it's necessary to set back the PID status and its
output to the initial values; this can be done with the "Reset Controller"
button.
• Beam OFF – this condition indicates that the beam intensity went below the
user defined "Beam Off Threshold" value (without going out of the ROC
region, see section 4.4 for more information) which indicates that beam was
shut down. In this condition the feedback is paused since it makes no sense to
stabilize a non-existing beam. If the beam intensity comes back again, the
feedback will be automatically moved from pause to Feedback ON state.
The "Enable/Disable Feedback" button allows to start or to stop the feedback
regulation of beam position to the selected setpoint.
The "Reset Controller" button resets all internal states (e.g. the integrated value of
error) of the PID controller.
The feedback configuration options are placed below the "Enable/Disable Feedback"
and "Reset Controller" buttons:
Figure 21: Feedback control section
for a visual representation of the PID structure).
Figure 23
User's Manual
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), which shows
Figure 20
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