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Control System Overview J. Frederick Bartlett Fermilab June 1,1999
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Online Workshop The DØ Control System History Run I - CDAQ Built at DØ VMS and Pascal Platform Independence Decree Run II - EPICS Shared with HEP Community Runs on many platforms The Standard (Control) Model Operator Interface (OPI) Local Area Network (LAN) Input/Output Controller (IOC)
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June 1, 1999Online Workshop The Standard Model OPI IOC OPI IOC LAN
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June 1, 1999Online Workshop Operating Systems OPI (Host) Operating System UNIX Digital UNIX Linux Windows NT IOC (Front End) Operating System VxWorks Real-Time Linux (later?) Platforms Motorola 68K (MVME-162) Motorola Power PC (MVME-230x)
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June 1, 1999Online Workshop EPICS Characteristics Maintained by HEP and astronomy community Tools and building blocks for a control system Distributed database Scalable architecture OPI’s and IOC’s may be added dynamically Channel Access (CA) servers and clients Event driven Portable CA Server Written in C++
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June 1, 1999Online Workshop EPICS Characteristics High performance (records processed per second) MVME-162 (68K) >5000 MVME-230x (Power PC) >50000 Extensive collection of applications Database editors Display programs Alarm handler Archiver Many more
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June 1, 1999Online Workshop EPICS Channel Access Channel access provides network transparent access to IOC databases CA Services Search - Find a process variable (PV) by name Get - Get a PV value + optional information PUT - Change the value of a PV Add Event - Add a change-of- state callback to a PV
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June 1, 1999Online Workshop EPICS Channel Access Items returned with a GET Value String Integer (char, short, int, long) Floating point (float, double) Enumerated menu string Optional Status and severity Time stamp Graphics and alarm limits Control limits Channel access transforms numeric formats native types
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June 1, 1999Online Workshop Asynchronous Provides a callback mechanism for change of state Alarms Value change Any Deadband Archival
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June 1, 1999Online Workshop IOC Components Channel Access Server Channel Access Server Scanners Record Support Device Support Device Driver Database Access IOC Database IOC Database Ethernet LAN Interrupt Receiver VME Bus Database Load
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June 1, 1999Online Workshop OPI Components User Application Ethernet LAN Channel Access Client Channel Access Client EPICS File Extractor Hardware Database Hardware Database EPICS.DB File EPICS.DB File CA Interface
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June 1, 1999Online Workshop Record Scanning Periodic - Process at a periodic rate Standard 0.1, 0.2, 0.5, 1, 2, 5, 10 seconds DØ may add other periods Event - Process when an event is posted 255 events Begin run, End run,... I/O Event - Process on an external interrupt Passive - Process only when requested
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June 1, 1999Online Workshop Database Access Levels Record Provides a generic user view of a device + attributes Simple records may be linked to provide complex behavior rm AD00 DA00 ai INP VAL ao OUT VAL
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June 1, 1999Online Workshop Database Access Levels Device Transforms device-specific characteristics Types VME bus MIL-1553B bus GPIB bus CANbus CAMAC Soft (linked to another record) Symbol (linked to
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June 1, 1999Online Workshop Database Access Levels Driver Required when a device generates interrupts
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