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BlissBrother is a PyTango device server designed to ease long time archiving of BLISS settings to be able to retreive a snapshot of the Beamline state over time.

For now, it reads only the position of all axes (including calculated axes) declared in a BLISS configuration.

According to users needs, archiving frequencies must be tuned to be useful and to not saturate HDB++.

Using Tango attributes has the advantage to be archived using HDB++ system and tools:

  • reliability: centralized mariaDB database
  • data retrieving: jhdbviewer + API

In short, BlissBrother server:

  • reads settings of user interest (for now: all axes positions) in Redis database;
  • exposes these values as tango attributes;
  • Stores them in HDB++ database according to defined policy (~ when they change, but not too often);

Configuration

Tango device server configuration

  • blacklist: string : list of axes separated by comas to not monitor OR path of a file containing blacklisted axes.
  • delta_time_still_motor: int: time interval (in seconds) to store motion-less motors.
  • still_time_before_saving: int: time (in seconds) to wait to store motor position if motor has moved.

To store attributes values in HDB++, BlissBrother DS must have access to a configurator server and the subscriber server.

Note

On a standard ESRF Beamline, the addresses of these servers can be automatically retreived from Tango Database HDB++ Properties:

  • configurator_url: url of the configurator server
  • archiver_url: url of the archiver server Screenshot

Example of Tango configuration: 

delta_time_still_motor: 1200
still_time_before_saving: 15
and optionnaly:

  • configurator_url: string: “//acs:10000/sys/hdb++config/id42”
  • archiver_url: string: “tango://acs.esrf.fr:10000/sys/hdb-es/id42”
  • blacklist: string: “~/local/beamline_configuration/bliss_brother_blacklist.txt”
  • blacklist: string: “sampy, zoom, ffsamy, ffsamz, samrot”

axes blacklist

Axes names added in blacklist will not be monitored. The blacklist can be a list of axes in DS configuration or a plain text file defined in DS configuration.

Blacklist file example: 

cat ~/local/beamline_configuration/bliss_brother_blacklist.txt

sampy, zoom,
ffsamy, ffsamz,
samrot

Database reading

Archived data can be retrieved using jhdbviewer or via HDB++ API.

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