1. Control System Overview J. Frederick Bartlett Fermilab June 1,1999

2. 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)

3. June 1, 1999Online Workshop The Standard Model OPI IOC OPI IOC LAN

4. 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)

5. 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++

6. 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

7. 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

8. 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

9. June 1, 1999Online Workshop Asynchronous  Provides a callback mechanism for change of state  Alarms  Value change Any Deadband Archival

10. 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

11. 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

12. 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

13. 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

14. 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

15. June 1, 1999Online Workshop Database Access Levels  Driver  Required when a device generates interrupts