Troubleshooting presence of snr.csv Files in Temp folder on NextSeq 500/550 (NCS 4.0.2)

Systems running NextSeq Control Software (NCS) v4.0.2 have numerous snr.csv files in the temporary run folder in D:\Illumina\NextSeq Control Software Temp.

SNR files have been introduced in the software and are expected to be present in the Temp folder. These are intended to help with signal-to-noise ratio debugging and do not get copied to the output run folder.

The local temp folders get automatically deleted by the NextSeq Control Software after a certain time period.

Example snr.csv files:

• 2021-01-11__19_07_54_32F03D30 GetBestZ Camera 1 Focus Red top surface.snr.csv

• 2021-01-11__19_07_54_32F398CF CalculateSignalStd(z[0]=0.019553, IQData len 18, imax 9, depthOfField 0.018).snr.csv

• 2021-01-11__19_07_54_32F4AA19 SafeParabola called by CalculateSignalStd.snr.csv

• 2021-01-11__19_07_54_32F6927F SafeParabola called by FindPeakUsingParabolaFit.snr.csv

Troubleshooting steps:

• Leave the files in the temporary run folders as they will be automatically deleted with all remaining files and do not affect sequencing quality or time.

• There is no setting to 'switch off' the file generation.

For any feedback or questions regarding this article (Illumina Knowledge Article #3878), contact Illumina Technical Support [e-mail].