P' Duhoux

1
LSF - the LCU Server Frameworkeasy creation of
LCU applications with Object Oriented approach

• P. Duhoux
• European Southern Observatory
• July 2002 TSW
  Tutorial

2
ATCS - the Initiator

• Large number of new sub-systems
• Control of standard devices (motors, signals,
  serial links, monitoring and background tasks)

3
LSF is a Framework

• Fixed design and architecture
• Improved code reuse thus reduced maintenance
  costs
• Enforce VLT standards

4
LSF is for SW Devices

• SW device must support Standard Commands at ACI
  and API level
• Behavior of standard commands is defined once
• Any number of specific commands may be added

5
LSF handles State SubState

• State machine is 100 LCC
• State transitions are fully defined while
  additional behavior may be implemented
• The concept of sub-state has been introduced that
  gives more precise information on the SW device
  status
• Automatic and systematic restoration of DB
  configuration at Initialization
• Monitoring activity allowed in any initialized
  state

6
LSF supports various devices

• LSF supports many types of standard devices
• All device types derive from the base device
• New device types can be easily added

7
LSF imposes the SW architecture

• Minimum behavior for all standard commands is
  provided
• Additional behavior by means of user defined
  hooks
• Table driven control
• Monitoring of device state and sub-state

8
LSF imposes the DB structure

• All classes are derived from the base class
  lsfDB_DEVICE
• A SW device is a kind of SoftDev
• Specificity is achieved by sub-classing

9
LSF database branch
Run-time data
Device types
Device instances
10
LSF supports Overloading

• Fixed thread of control for all standard commands
  with several hooks for additional behavior
• sub-SW devices are always handled first

11
LSF schedules the Activities

• The state and sub-state of a device are updated
  during the activities.
• All devices of a type are processed
  simultaneously

12
LSF Base Device

• Minimum classes for all the devices

13
LSF Devices

• All device types are built on the same scheme
• The device types are providing all minimum
  behavior as of the associated HW device

14
lsftpl - the Application Template 1

• Template application used both for tests and for
  the creation of new applications
• Fully scalable to the needs of the new
  application
• Provides implementation examples for most of the
  device types

15
lsftpl - the Application Template 2

• The creation of a new module is based on 3
  utilities
• lsfCreate create an instance based on the
  template
• lsfConfig customize the module to the needs
• lsfBackup generate a DB backup file
• It requires the edition of a couple of files
  prior to invoking lsfConfig

lsfCreate app
Edit some files
lsfConfig app
Build application Build WS LCU environments
Load on LCU Tune devices
cmmArchive app
lsfBackup
16
Maintenance Tests

• Core is implemented once in lsf
• standard behavior can easily be modified/improved
• all lsf-based applications updated at once
• Minimum tat test provided with the template
• only specific tests shall be implemented

17
LSF is a Standard

• LSF has (shall) become the de-facto standard for
  all new LCU applications (INS excluded).
• All new VLTI sub-systems are based on lsf
• ATCS
• OPD, Transfer Optics (M16 and Temperature
  Sensors)
• VCM
• FINITO
• Coudé
• MACAO VLTI (RTC and ICS parts)
• Future applications
• PRIMA FSU and Metrology
• SINFONI, CRIRES ???

18
Conclusions

• LSF has now been instantiated about 30 times in
  various configurations in the last 18 months.
• Most of the maturity problems have been solved
  and it shows a good level of reliability
• LSF re-inforces our standards
• LSF allows the designer to concentrate on the
  application specific issues