This screen is used to access and control the four sweep detectors. For each detector the following controls and indicators are shown here (each PV is prefixed with $(device):$(axis) and n runs from 0 to 4):
| PV | Description |
|---|---|
:DET:n:ENABLE_S | Each detector can be enabled or disabled. Normally the only reason to disable detectors would be so that the entire detector memory is available for a very long experiment. |
:DET:n:SCALING_S | If the sweep is configured for a very long dwell with a high input level then it is possible for the detector to overflow; this control can be used for a further 8 bits of dynamic range. |
:DET:n:COUNT | This PV indicates how many bunches are being captured by this detector. |
:DET:n:MAX_POWER | This PV indicates how much dynamic range is available in the detector: if this approaches 0dB then |
:DET:n:OUT_OVF | This PV will indicate an error if the last detector capture generated an overflow. |
For each detector buttons link to two screens:
| Title | Link | Description |
|---|---|---|
| Waveforms | Detector Waveforms | Screens for viewing waveforms captured by the detector. |
| Bunches | Detector Bunch Enables | Configuration screen for editing :DET:n:BUNCHES_S. |
The setup section of this screen provides the following controls and indicators:
| Title | PV | Description |
|---|---|---|
| Source | :DET:SELECT_S | Normally the data to each detector should be passed through the FIR, if only to reject the bunch by bunch fill pattern, but it is possible to select the raw ADC data as an alternate source. |
| FIR delay | :DET:FIR_DELAY_S | This can be set to the group delay of the FIR filter so that this delay is compensated for in the detector. However, we have discovered at DLS that setting this to anything other than 0 is confusing. |
| ADC no fill length | :ADC:REJECT_COUNT_S | This is a copy of the fill reject length control on the ADC Setup page. |
| Captured | :DET:SAMPLES | This records the number of samples captured in the last sweep. |
| Underrun | :DET:UNDERRUN | This should never indicate anything other than "Ok", an error here indicates a worrying internal FPGA problem, or possibly an unreasonably small bunch count. |
| Waveforms | :DET:FILL_WAVEFORM_S | This is a fudge to help EDM, and should otherwise be set to "Truncated". This will probably be deleted. |
Note that 8M (8388608) samples of detector memory are available for capture, but if all four detectors are enabled then only 2M samples per detector are available. Also note that if more samples are captured than will fit into memory then the early samples will be silently overwritten and there will be no warning indication.
On the bottom right two buttons link to related screens:
| Title | Link | Description |
|---|---|---|
| Tune | Tune Fitting Overview | Link to tune fitter. Note that only tune fitting for the first detector is available. |
| SEQ Trig | Trigger Target Setup | Trigger configuration for sequencer trigger |