Quality Attributes

Overview

Low CBF publishes telescope- and subarray-level quality figures that let operators judge the quality of the Low CBF signal-processing outputs — delay readiness, Jones-matrix application, SPS RMS levels and flagging, link-up and host resolution. These figures are exposed as Tango attributes on the quality device low-cbf/transducer/quality, aggregated from the underlying Allocator, Subarray, Processor and Connector devices, and refreshed every few seconds.

Published quality attributes

Attribute

Type

Description

processorsReadyPercent

JSON map

Per-subarray percentage of processors ready.

processorEthernetLockedPercent

JSON map

Per-subarray percentage of processors ethernet locked.

spsLinkUpPercent

Double

Telescope-wide percentage of SPS ingest links that are up.

cbfPacketLossRate

Double

Telescope-wide percentage of SPS ingest links packet loss rate.

cbfPacketCorruptionRate

Double

Telescope-wide percentage of SPS ingest links packet corrupted rate.

pssHostsResolvedPercent

JSON map

Per-subarray percentage of PSS destination hosts resolved.

pstHostsResolvedPercent

JSON map

Per-subarray percentage of PST destination hosts resolved.

sdpHostsResolvedPercent

JSON map

Per-subarray percentage of SDP destination hosts resolved.

stationBeamDelayReadyPercent

JSON map

Per-subarray percentage of station beams with valid delays.

pstBeamDelayReadyPercent

JSON map

Per-subarray percentage of PST sub-beams with valid delays.

pssBeamDelayReadyPercent

JSON map

Per-subarray percentage of PSS sub-beams with valid delays.

pstJonesAppliedPercent

JSON map

Per-subarray percentage of PST beams with a Jones matrix applied.

pstJonesAge

JSON map

Per-subarray mean age (seconds) of the applied PST Jones matrices.

spsRmsInRange

JSON map

Per-subarray percentage of SPS RMS samples within the accepted range.

spsFlagsPercentMean

JSON map

Per-subarray mean SPS flagged-sample percentage.

processorFpgaTemperatureMean

JSON map

Per-subarray processors mean temperature.

processorFpgaPowerMean

JSON map

Per-subarray processors mean power.

JSON output format

Every per-subarray attribute above (type “JSON map”) is a Tango string attribute whose value is a JSON object mapping a subarray id to a value:

{"<subarray_id>": <value>, ...}

  • Keys are the integer subarray ids, encoded as JSON object keys (i.e. strings, e.g. "1").

  • A value is null when the figure cannot be computed for that subarray (for example, no data has yet been reported for it).

  • The map contains only the subarrays that are currently configured, so it scales to any number of subarrays.

Example (stationBeamDelayReadyPercent):

{"1": 100, "2": 75, "3": null}

Here subarray 1 has all station-beam delays valid, subarray 2 has three quarters valid, and subarray 3 reported no usable data.

spsLinkUpPercent is the one exception: it is a plain scalar Double (telescope-wide), not a JSON map.

Attribute detail

Processor readiness and Ethernet

  • processorsReadyPercent — per subarray, the percentage of the subarray’s assigned processors that are ready (reporting a ready stats mode and an OK health state).

  • processorEthernetLockedPercent — per subarray, the percentage of the subarray’s assigned processors whose ingest Ethernet link is locked (the processor reports its link locked and the matching switch port is up).

Both are {subarray_id: percent} maps and are null when the subarray is not in READY or SCANNING, or has no processors assigned:

{"1": 100, "2": 50, "3": null}

CBF packet loss and corruption

  • cbfPacketLossRate — the fraction of CBF SPEAD packets lost, aggregated over the processors the Allocator has currently assigned to a subarray. Derived from per-processor SPEAD counters as missing / (received + missing) over the interval between refreshes.

  • cbfPacketCorruptionRate — the fraction of CBF SPEAD packets corrupted (bad Ethernet packets), over the same denominator.

Both are plain scalar Double values (telescope-wide), expressed as a fraction in the range 0.0–1.0. With no processors allocated the counters are empty and both resolve to 0.0.

Delay readiness

stationBeamDelayReadyPercent, pstBeamDelayReadyPercent and pssBeamDelayReadyPercent give, per subarray, the percentage of beams that currently have valid delays — at the station-beam, PST sub-beam and PSS sub-beam levels respectively.

Each is a {subarray_id: percent} map, with null where no delay data is available:

{"1": 100, "2": 88, "3": null}

PST Jones (applied % and age)

Jones figures are PST only — there is no PSS Jones data, so there are no pssJones* attributes.

  • pstJonesAppliedPercent — per subarray, the percentage of configured PST beams that have had a Jones (calibration) matrix applied.

  • pstJonesAge — per subarray, the mean age in seconds of the most recently applied PST Jones matrices. A beam that has not yet had a matrix applied counts as 3600 s (1 hour) old. The figure is null when a subarray has no PST beams reporting.

Both are {subarray_id: value} maps — a percentage for pstJonesAppliedPercent, a mean age in seconds for pstJonesAge:

{"1": 100, "2": 50}

{"1": 12, "2": 3600}

SPS RMS-in-range and flags percent

  • spsRmsInRange — per subarray, the percentage of SPS RMS samples (across both polarisations) that fall within the accepted range. The range bounds are configurable and default to 10–30.

  • spsFlagsPercentMean — per subarray, the mean percentage of SPS samples that are flagged.

Both are {subarray_id: percent} maps, and are null for a subarray that reports no SPS data:

{"1": 97, "2": 100, "3": null}

Processor FPGA temperature and power

  • processorFpgaTemperatureMean — per subarray, the mean FPGA core temperature (degrees Celsius) across the subarray’s assigned processors.

  • processorFpgaPowerMean — per subarray, the mean FPGA power draw (watts) across the subarray’s assigned processors.

Both are {subarray_id: value} maps — degrees Celsius for temperature, watts for power — and are null where the subarray has no processors assigned:

{"1": 41.5, "2": 39.8, "3": null}