3rd April 2001 A.Polini and C.Youngman 1 GTT status • Items reviewed: – Results of GTT tests with 3 MVD-ADC crates. • Aims • Hardware and software setup used • Credit control implementation • Latency and rate results - test 1 • Latency and rate results - test 2 • System acceptability – GTT time schedule and requirements on ZEUS DAQ.
GTT status. Items reviewed: Results of GTT tests with 3 MVD-ADC crates. Aims Hardware and software setup used Credit control implementation Latency and rate results - test 1 Latency and rate results - test 2 System acceptability GTT time schedule and requirements on ZEUS DAQ. - PowerPoint PPT Presentation
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3rd April 2001 A.Polini and C.Youngman 1
GTT status
• Items reviewed:– Results of GTT tests with 3 MVD-ADC crates.
• Aims
• Hardware and software setup used
• Credit control implementation
• Latency and rate results - test 1
• Latency and rate results - test 2
• System acceptability
– GTT time schedule and requirements on ZEUS DAQ.
3rd April 2001 A.Polini and C.Youngman 2
Results of tests with 3 MVD-ADC crates• Aims
– Implement the credit controlled GTT described in ZEUS Note 99-74 with data input from 3 MVD-ADC crates.
– Measure latency and rate characteristics in the absence of algorithm data processing in week available.
– Make a statement about the acceptability of the system w.r.t. the ZEUS DAQ.
• Hardware and software setup used– parts of the MVD test system as of 23/3/01
• 3 complete and fully debugged ADC/readout crates.• Clock&Control system incl. Pulse generator ext. trigger.
• PPC VME (fast) and PC(giga) CPUs connected to separate ports
– MVD run control and monitoring software.
3rd April 2001 A.Polini and C.Youngman 3
GTT credit control implementation
• keypoints– code derived from a non hardware simulation
• allows RC configurations to be tested
• allows message and IP connectivity to be debugged
– uses a common function library for buffering• ordering of events with GFLT# before sending to GSLT/EVB
• gathering complete events at GTT and EVB
– network messages sent consists of:• an short control message (<128B) in XDR tagged union.
– endian independent
– contents (GFLT#,etc.) remove the need to look into the data
• and, optionally, a data message.
– all programs are currently single threaded.
3rd April 2001 A.Polini and C.Youngman 4
1 1 1
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2 2 2
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GFLT ACCEPT
GSLT DECISIONEVBGSLT
MVD-ADC STT-SLTCTD-SLT
GTT
TOEVB TOGSLT FROMGSLT
1 1
3
26
8
7 54
0/6
1
1 2
GTT process, network and trigger connections - credit based.
3rd April 2001 A.Polini and C.Youngman 5
Control message definitions
• Credit– 0. credit number allocation (SETUP)
– 1. credit/socket resolution (SETUP)
– 2. credit list (SETUP) and credit notification (ACTIVE)
• Trigger– 3. SLT data to GTT (ACTIVE)
– 4. GTT end algorithm credit notification (ACTIVE)
– 5. GTT algorithm result to GSLT (ACTIVE)
– 6. GSLT decision to MVD and specific GTT (ACTIVE)
• EVB– 7. GTT result and MVD cluster data (ACTIVE)
– 8. MVD strip data (ACTIVE)
3rd April 2001 A.Polini and C.Youngman 6
1 1 1
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2 2 2
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2 1
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2 24
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GFLT ACCEPT
GSLT DECISIONEVB GSLT
MVD-ADC STT-SLTCTD-SLT
GTT
TOEVB TOGSLT FROMGSLT
1 1
3
26
8
7 54
0/6
1
1 2
GTT hardware realization
3rd April 2001 A.Polini and C.Youngman 7
Latency and rate results - test 1• Fix SLT & EVB data size/crate and vary N GTT
– measurement parameters• SLT size/crate 2.6, 2.7 and 1.9 kB• EVB size/crate 4.6, 4.6 and 3.3 kB• vary N GTT through: 1,2,4,8,12,18,24 and 30 (ie. 5/PC).• Pulse generator rate 600 Hz.• GSLT accept prescale factor 10
– results are independent of N GTT• Sustained rate 500 Hz mean with 60 Hz p2p fluctuation.• Latency at TOGSLT 1.7ms with low level but long tail.• Latency at TOEVB 2.9ms - did not look at tail.
• N GTT independence surprising especially for 1 GTT, understood ?• rate and fluctuation not understood, credit bursting ?.• latency tails not understood, more detailed tests required.
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GTT latency at TOGSLT
3rd April 2001 A.Polini and C.Youngman 9
Latency and rate results - test 2• Fix N GTT and vary SLT & EVB data size/crate