1st ACS Workshop, Garching. 08-09 March, 2004

ACSACSandand

VLT Common softwareVLT Common software

G.Chiozzi

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ACS and VLT Common Software

Contents

• ACS versus VLT Common Software• Integration and step-by-step migration• An ACS instrument on a VLT telescope• Java/Python for high level software• Joining the services• Conclusions• Questions & Answers

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ACS and VLT Common Software

ACS versus VLT Common Software

• VLT Common Software (CCS) development started ~12 years ago:

mature and stable

• ACS development started 5 years ago: newer technology, still under development

• ACS has learned a lot from CCS:– Many similar architectural concepts– Improvements based on lessons learned

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ACS and VLT Common Software

Kitt Peak test: 2000

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ACS and VLT Common Software

Integration and step-by-step migration

• The VLT is in operation• The software works reliably and is adequate to the

requirementsThere is no compelling reasons to replace it NOW

BUT

• Some software and hardware components will become soon obsolete

• It is necessary to identify an evolutionary pathACS can provide this path

because it is coherent with the CCS architecture

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ACS and VLT Common Software

An ACS instrument on a VLT telescopeTelescope Interface - TIF

Commands

Database

Events

VLT telescope

ACS instrument

ACS TIF

IDL

interface

TIF DSI Component

CCS RTDBdevIO

Notification Channel

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ACS and VLT Common Software

New ACS-based high level SW

The same strategy can be applied to any CCS Server process

Once a server has an “ACS view” it is possible to implement:– Java co-ordination software– Java GUIs with Abeans– Python scripts

and to use ACS tools like Object Explorer

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ACS and VLT Common Software

Joining the services

• Some basic ACS/CCS services need to be harmonised. In particular:– Logging System

– Error System

• In the scenario of integrating ACS applications in the existing CCS infrastructure:– An ACS Logging Client can receive ACS logs and convert them in

the protocol used by the CCS logging system

– An Error Wrapper must allow to convert between ACS and CCS error traces, in both directions

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ACS and VLT Common Software

Conclusion

• We have proofed that ACS and CCS can coexist

• We have started a couple of pilot projects to make real scale tests

• We will have to select carefully where to introduce ACS. This must be in areas were we obtain real advantages with respect to CCS

• On the long term this gives us an upgrade path, so that we can stepwise replace components that become obsolete.

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ACS and VLT Common Software

Questions (& Answers)