NDTS Experiment Harvesting

Identifying acquisition start and end events

The daemon detects when TopSpin or VNMRj is launched, who launched it, and whether it controls the spectrometer. How experiment start and end events are detected varies depending on the software version controlling the spectrometer:

• VNMRj - the daemon listens to InfoProc network messages to detect transitions in status (e.g. idle to acquiring)
• TopSpin 3.x - the daemon uses inotify (ReadDirectoryChanges on Windows) to monitor changes to the accounting file. See additional details on how NDTS utilizes the TopSpin accounting file here:
  • accounting must be enabled on a per user basis. See enabling TopSpin accouting for more details.
  • only detects experiment end events. The experiment start time is determined after the experiment is complete
• TopSpin 4.x - the daemon monitors the shmem file in the user-specific TopSpin directory ({topspin_directory}/prog/curdir/{user}/shmem) for start and end events

Sessions

Each dataset harvested is associated with a sessionID. New sessions are created when:

• a user logs in to the workstation
• when a user starts the spectrometer software that controls the spectrometer (VNMRj or TopSpin)
• when the NAN User is changed in the NDTS-GUI

Experimental datasets with the same experiment name (e.g. expN for VnmrJ, and data_directory/N for TopSpin) and the same sessionID are all tagged as redundant except for the most recent experiment which is tagged preferred. The preferred / redundanat status can later be altered by the user from the Dataset Browser.

Datasets that are skipped automatically

NDTS Audit File

The NDTS audit file will show detailed records of every dataset that the daemon detected and what what the status of the transfer is (e.g. sent, spooled, skipped).

Limitations

NDTS is off

paropt

missing critical data