Diagnostic scope traces

The Ketek can collect diagnostic scope traces of pre-amp input signal and the outputs of several stages of the digital pulse processing. These are very useful for diagnosing issues with the input and examining the outputs of the various digital filters.

The trace can be collected instantly when the ScopeRead record is processed, or after a specific trigger condition is satisfied. If there is a trigger then it will be in in the middle of the trace, i.e. at point 4096, so there are equal numbers of pre-trigger and post-trigger samples.

These are the records to control diagnostic traces. The records are contained in ketek.template.

EPICS record names

Record types

drvInfo string

Description

ScopeRead

bo

KetekScopeRead

Arms the system to capture trace data on the next trigger event.

ScopeData

waveform

KetekScopeData

Waveform record containing the diagnostic trace data. 8192 elements, 32-bit integer data type.

ScopeTimeArray

waveform

KetekScopeTimeArray

Waveform record containing the time values for each point in ScopeData. 64-bit float data type.

ScopeInterval, ScopeInterval_RBV

ao, ai

KetekScopeInterval

Time per sample of the scope trace data in microseconds. Allowed range is 0.0125 to 819.2.

ScopeDataSource, ScopeDataSource_RBV

mbbo, mbbi

KetekScopeDataSource

The type of data to be captured. Choices are:

  • ADC data

  • Fast filter

  • Medium filter

  • Slow filter

  • Baseline average

  • Baseline sample

EventTriggerSource, EventTriggerSource_RBV

mbbo, mbbi

KetekEventTriggerSource

The trigger event to wait for. Choices are:

  • Instant

  • ADC value

  • ADC out of range

  • Fast trigger

  • Fast reset

  • Fast pileup

  • Medium trigger

  • Medium reset

  • Medium pileup

  • Output count

  • Output Energy

  • Baseline sample

  • Dyanamic reset

EventTriggerValue, EventTriggerValue_RBV

longout, longin

KetekEventTriggerValue

The trigger value.

ScopeTriggerTimeout, ScopeTriggerTimeout_RBV

ao, ai

KetekScopeTriggerTimeout

The timeout to wait for the trigger to occur after ScopeRead is processed. Choices are [1, 2, 4, 8, 16] seconds.

The following are the MEDM screen ketekTrace.adl displaying several diagnostics traces. These were done with a Cd109 source, which produces Ag K x-rays.

The following trace was done with ScopeDataSource=”ADC data”, ScopeInterval=1.0 microseconds, EventTriggerSource=”Fast reset”. The total time is 8192 microseconds. The reset event is a time=4096 microseconds, in the middle of the trace. The small positive steps are the Ag K X-ray events.

_images/ketek_adc_trace.png

The following trace was done with ScopeDataSource=”Baseline sample”, ScopeInterval=0.0125 microseconds, EventTriggerSource=”Instant”. The total time is 102.4 microseconds.

_images/ketek_baseline_sample_trace.png

The following trace was done with ScopeDataSource=”Baseline average”, ScopeInterval=10.0 microseconds, EventTriggerSource=”Fast reset”. The total time is 80192 microseconds.

_images/ketek_baseline_average_trace.png

The following trace was done with ScopeDataSource=”Fast filter”, ScopeInterval=2.0 microseconds, EventTriggerSource=”Instant”. The total time is 16384 microseconds.

_images/ketek_fast_filter_trace.png