# Presentation: 740956

## DØ DAQ Status

- June 17th, 2002
- S. Snyder (BNL), D. Chapin, M. Clements, D. Cutts,
- S. Mattingly (Brown), B. Angstadt, G. Brooijmans,
- D. Charak, G. Guglielmo, M. Johnson, S. Fuess,
- A. Kulyavstev, M. Mulders, R. Rechenmacher, D. Slimmer, D. Zhang (Fermilab), R. Hauser (MSU),
- P. Padley (Rice), A. Haas, G. Watts (Washington)

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Commodity DAQ System

- DØ Detector

- FCC

- 1 kHz

- 1 kHz

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

- Single Board Computers (SBC) read the event data over the VME bus, and send it to a Level 3 node over Ethernet, according to routing instructions received from the *Routing Master*
- The Routing Master program runs on an SBC in a special crate receiving data from the Trigger Framework (and can disable individual trigger bits if needed).
- Event building is done in the Level 3 nodes.

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Hardware Components

- Single Board Computers:
- require good processor speed, enough memory, Ethernet, fast VME access, two channels of digital I/O (readout handshakes).
- chose VMIC 7750: 933 MHz PIII, 128 MB RAM, 2 Ethernet ports, Tundra Universe II for VME-PCI interface.  Added BVM digital I/O card.
- One custom component: passive extender board to fit 6U SBCs in 9U crates.

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

- Switches:
- Cisco 2948G (“concentrators”): 100 Mb/s (copper) input from SBCs, Gb (fiber) output.  Limit to 10 SBCs per fiber  no congestion possible
- Cisco 6509: capable of handling 16 GB/s (average expected rate is 250 MB/s).  Gb fiber in (from 2948G’s), 100 Mb/s (copper) out to Level 3 Nodes, with 112 MB of buffering in the switch per 48 nodes.

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Software Components

- Run
- Control

- L3
- Control

- TFW
- SBC

- SBCs

- Routing
- Master

- Filter
- Nodes

- FCC

- Run Configuration Info

- Data Flow

- Routing Info

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Single Board Computer Software

- Interrupt Processing

- In Linux User Space

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Routing Master

- ~70 SBC’s**Read out crates**Send data to Nodes as routedby *tags* received from the RM

- ~100 Nodes
**Process data, run filters**
- Send number of free buffersback to the ETG

- ~100 Nodes
**Process data, run filters**
- Send number of free buffersback to the ETG

- ~100 Nodes
**Process data, run filters**
- Send number of free buffersback to the ETG

***Data***

- Routing
- Master (RM)
- - Gets trigger bits fired
- - Decides which cratesneed to be read out
- - Tells SBC’s which node(s) to send data to
-  Sends TFW block to correct node(s)
- - Enables/disablestriggers- Heart of monitoring / run configuration / error reporting

- 10 Hz / Node
- 8 bytes

- 100 Hz / SBC~200 bytes

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Status

- Go-ahead given at the end of December
- Software conversion made on March 26th
- Finished replacement of VBD’s with SBC’s on June 5th (6 weeks ahead of schedule)
- Started L3 input rate increase (from previous 100 Hz):
- in April, demonstrated all readout crates can go at at least 1.17 kHz for evenly spaced triggers
- For random triggers, problems in L1 muon readout around 550 Hz.  Problem is understood (buffering of L2 accepts), working on firmware

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Prospects

- Increase in L3 input rate during physics running requires
- DAQ and front-end capability
- Can do 550 Hz now, don’t expect many new problems between 550 Hz and 1 kHz
- Adequate rejection at L3 (we were running at 100 Hz in, 25 Hz out, now want to go 1 kHz in, 50 Hz out  need to increase rejection by 5)
- Studies being done, strategy being formulated
- Enough cpu capacity in L3 farm
- Benchmark tests done, purchasing additional 32 nodes (total will be 80)

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002

## Summary

- Hardware and software conversion of the DAQ system are complete
- Commissioning increase in L3 input rate:
- Working on L1 muon problem
- Developing L3 trigger strategy
- Purchasing additional L3 nodes to satisfy cpu requirements
- My best guess: DØ operating at O(500) Hz in, 50 Hz out in July & August, 1 kHz/50 Hz starting in September

- Gustaaf Brooijmans - All Experimenter's Meeting

- June 17th, 2002