QUICK HELP
To completely restart this longitudinal feedback when all is lost...
1) STOP the feedback ---- once stopped you probably have to manually bring beam back ...
2) verify the State Setpoints (and limits) are set to values you want - you can type them in under the Setpoints column.
---The L2 Chirp setpoint (in grey) should be set equal to the L2 Chirp readback at the lower right.
3) verify the Actuator Setpoints (and limits) are set to values you want - you can type them in under the Setpoints column whenever the FCOM column indicates it is OFF.
----You also may want to Update Act Refs at this point
4) ZERO ACTUATOR OFFSETS - button in top section; this sets all the LLRF timeslot offsets to zero for feedback stations L0B, L1S, L2 and L3
5) disable all individual states DL2 Energy, BC2 Energy and Chirp, BC1 Energy and Chirp, DL1 Energy
6) START the feedback - it will display messages as it connects to actuators,
7) enable each state one at a time starting with DL1 Energy - you can watch them start up on the Plots...
Detailed Help for Longitudinal Feedback
WARNING: The controls on this screen perform INVASIVE operations.
This Help screen applies to all Longitudinal Feedbacks currently operating; there are seven feedback configured up through BC2. The longitudinal feedbacks adjust the phase and / or amplitude of the L0B RF, L1S RF,and L2 24-1 and 24-2 phasesfeedback adjust the L0B amplitude, L1S amplitude and phase, L2 amplitude and phase, and L3 amplitude, in order to maintain the desired energy and / or bunchlength peak current at different points along the beamline. The DL2 Energy portion is not yet operational.
The desired Energy and Bunchlength Peak Current values (State Setpoints) are set by the operator on this screen.
This screen is arranged in three sections.
SECTION ONE: Longitudinal Feedback Control
This section, across the top of the display, is a duplicate of the controls on the Feedback Control display, and they work the same way. It contains the controls as one line item for the associated longitudinal feedback. Please see the Help... for the Feedback Control display for a description of these indicators and control buttons.
SECTION TWO: Feedback Detail Graphic
This middle Section shows a graphic of the position of the devices used in the associated Feedback application. The device name is a button which brings up the related device display. There is a square of color that indicates whether the device is currently used in the Feedback. Green means it is in-use, Grey means it is not used. If it is Red or Yellow, then the device or state is in a warning or error condition. See the tabular display below to see if the device or state is operating near or outside of its limits.
This section also contains the individual state loop controls. you may choose to Activate or Disable the state loops individually using the Activated/Disabled toggle button for each state.
SECTION SECTION THREE: Tabular Data Display and Controls
This section shows a table of the lower limit, current value, and upper limit of measurements collected for the associated Feedback, and the calculated States and actuator values. When the feedback is on the current values will update continuously. If a device or state is operating near its limits, or out-of-range, the current value will be highlighted with a corresponding yellow or red box around it. You can enter new limits on-the-fly using these inputs.
There are six several 'setpoint' inputs available in the section for the operator. The operator may change most of these setpoints 'on-the-fly', the feedback will read the new setpoint on the next iteration. The setpoints outlined in a grey box can only be changed when the feedback, or the associated individual loops, are off or disabled / compute.
The on-the-fly setpoints can all be used as a vernier to scan around the setpoint.
The on-the-fly setpoints are:
DL1 Energy: The desired Energy for Dog Leg 1, in MeV.
BC1 Energy: The desired Energy at Bunch Compressor 1, in MeV.
BC1 BunchlengthPeak Current: The desired Bunchlength Peak Current after Bunch Compressor 1, in percent???
BC2 Energy: The desired Energy at Bunch Compressor 2, in MeV.
BC2 BunchlengthPeak Current: The desired Bunchlength Peak Current after Bunch Compressor 2, in percent???
DL2 Energy: The desired Energy for Dog Leg 2, in MeV. (not yet available)
Graphs... button
This is most often used as a 'vernier' around the actual DL2 Energy value.
The setpoints that can be changed when the feedback is off are:
L2 Chirp: use this PV when the feedback is inactive, the same as you would the L2 Chirp MeV PV on Joe's display.
L2 Energy: use this PV when the feedback is inactive....
L0B Amplitude: set the L0B amplitude by hand here - same PV as on L0B RF display and Joe's 6x6 display
L1S Amplitude: same PV as on L1S RF display and Joe's 6x6 display
L1S Phase: same PV as on L1S RF display and Joe's 6x6 display
L2 Amplitude: same PV as the l2 'On Crest' Amplitude MeV on Joe's 6x6 display
L2 Phase: same PV as the l2 Phase on Joe's 6x6 display
L3 Energy: same PV as the L3 Energy MeV on Joe's 6x6 display
Plots button:
The Plots button will bring up plots of the longitudinal states, actuators and measurements data. these PVs contain the data actually used and calculated by the feedback. For this multiple pattern feedback, the plots displayed initially show PVs containing all data from all patterns. You can also see data from the individual patterns by choosing the Pattern 1... Pattern 2... buttons. When the beam is rate-limited, the display of the combined PVs looks strange due to aliasing of the data rate vs. the update rate of the plot. When rate limited it is best to look at Pattern 1 dataThis button brings up a display that contains continuously updating graphs of the Measurements, States, and Actuators for this feedback.