PVs

This page describes the data held by each PV served by this IOC.

See also

kafka_dae_diagnostics.data.Data for the data-model used by this IOC.

Static PVs

EVENTS / TOTALEVENTS

The total number of non-vetoed neutron events seen during the current run.

MEVENTS

Millions of events seen during the current run. Equivalent to EVENTS divided by \(10^6\).

EVENTMESSAGES

The number of event messages (e.g. ev44 schema) processed during the current run. This includes vetoed messages.

EVENTMODEFILEMB

Mebibytes of event messages (e.g. ev44 schema) processed during the current run. This includes vetoed messages.

COUNTRATE

The average count rate of the current run, in millions of events per hour.

This only includes good events.

EVENTMODEDATARATE

The average data rate of event messages in the current run in MiB/s. This includes vetoed messages.

HISTMEMORY

Memory used by diagnostic histograms, in MiB.

This is num_periods * num_spectra * num_time_channels * 8 bytes.

GOODFRAMES / RAWFRAMES

Number of ISIS frames in the current run.

GOODFRAMES counts only non-vetoed frames, RAWFRAMES counts both vetoed and non-vetoed frames.

GOODFRAMES_PD / RAWFRAMES_PD

Array of good/raw ISIS frames in the current run, keyed by period number. The array has length NUMPERIODS.

Note

The sum of this array may differ from GOODFRAMES if frames with an invalid period number are received. Those frames will be included in GOODFRAMES, but will not appear in GOODFRAMES_PD.

GOODUAH / RAWUAH

Accumulated micro-amp-hours in the current run.

GOODUAH counts only micro-amp-hours for the non-vetoed frames, RAWUAH counts both vetoed and non-vetoed frames.

GOODUAH_PD / RAWUAH_PD

Array of good/raw micro-amp-hours in the current run, keyed by period number. The array has length NUMPERIODS.

Note

The sum of GOODUAH_PD may differ from GOODUAH if frames with an invalid period number are received. Those frames will be included in GOODUAH, but will not appear in GOODUAH_PD.

NUMPERIODS

Number of periods configured in the current run. Valid period numbers are strictly less than this number.

NUMSPECTRA

Number of spectra configured for the diagnostic histogram of the current run.

NUMTIMECHANNELS

Number of time channels configured for the diagnostic histogram of the current run.

START_TIME / STOP_TIME

The most recent run-start and run-stop timestamps.

RUNDURATION

Duration, in seconds, of the current or most recent run.

PROCESSINGLAG

Estimated time difference, in seconds, between an event being emitted by the streaming hardware and being processed by the diagnostics IOC. This assumes that the clock in the streaming PC is reasonably well synchronised with the GPS clock used by the streaming hardware.

DIAGNOSTICSLAG

The amount of time taken, in seconds, between diagnostic PV updates. After an event message is processed by the diagnostics IOC, the corresponding update will not be published to PVs until this interval next expires.

Dynamic PVs

These PVs are created on-the-fly by kafka_dae_diagnostics. The PV will not exist if the requested period or spectrum is outside the range currently configured.

SPEC:<period>:<spectrum>:X

These PVs provide the X points (the time-of-flight bin centres) for a time of flight spectrum. This array has length NUMTIMECHANNELS.

SPEC:<period>:<spectrum>:Y

These PVs provide the Y points (the number of counts in the relevant bin) for a time of flight spectrum. This array has length NUMTIMECHANNELS.