The k1bcst0 transmits 1 second-long data every second. However, when an IPC glitch occurs, the transmission occurs at intervals slightly less than 1 second from the previous transmission (Approximately 0.000 to 0.004 seconds faster. However, this number is not an accurate representation of the actual time of change, as it is not known how quickly the Frame_Log used for testing can respond to the arrival of a new frame.) This data is input to the low latency calibration pipeline, and its output is transferred to the Kashiwa by Framelink and further transferred to the CIT by Kafka. The IPC glitched data arriving at CIT was delayed about 1 second more than normal frames. As a result, the gwistat displayed on KAGRA status switches from Observing to Down, and Duration is reset to 0, even though KAGRA keeps locked and observing state. It is not yet known at why the data is transmitted early in the first place and what stage the data transmitted early is slowed down (Negative delay@k1bcst0 --> positive delay@CIT).
In low latency data stream, there is a loss of one frame approximately every few 10k seconds, which may also be resetting Duration on gwistat to 0. It is not yet clear at what stage this missing is occurring.
KAGRA status is sometimes shown as Down on the gwistat page even though the KAGRA interferometer is in Observing Mode and the summary page in KAGRA shows it as Observing Mode. This phenomenon occurs with a frequency of about a few hours per day. It is not yet clear what is causing it yet.