July 28, 2015 Cal F250

Video Conferencing Information

Meeting Time:

1. To join via a Web Browser, go to the page [1] https://bluejeans.com/907185247.
2. To join via Polycom room system go to the IP Address: 199.48.152.152 (bjn.vc) and enter the meeting ID: 907185247.
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Participant Direct Lines

• JLab Phone: in CC F326 is 757-269-6460 (usual room)
• JLab Phone in CC L207 is 757-269-7084
• Phone in the Regina Video-conference Suite is 306-585-4204

Action Items

List of issues:

• Handling of pedestal subtraction for late pulses (leading to negative values)
• Why is the overhead in the file size so large (content is about 20%)?

FA125's Useful Links

• FA250 modes 2 from Ed and Hai, Feb 18 2014
• FIRMWARE for FADC250 Ver2 ADC FPGA, Sept 2014?
• Format doc version 5.06, 23 June 2015
• Timing algorithm wiki page - updated to include latest revisions
• Data format for 250 modes on fADC125 from Cody, Aug 15 2014
• FDC_pulse_data_format
• CDC readout needs Garfield calcs

References

• Media:FADC125 DataFormat v5 06.pdf
• GlueX-doc-2752 fADC250 Operational Characterization: Air Flow, Temperature and Pedestals

Tentative Agenda

1. Announcements
2. Action Items
3. Log Entry 3346781 Estimates of peak: MC study of resolution (Elton)
4. Log Entry 3346042 Correlation coefficients between samples (Elton)
5. Discussion of data formats
   • e-mail exchanges
6. Any other business

Minutes

Attending: Elton, Fernando, Beni

1. Announcements
2. Action Items
3. Log Entry 3346781 Estimates of peak: MC study of resolution (Elton)
   • Conclusion from study is that there is no clear advantage to more complicated algorithms for determining the peak compared to using the maximum sample
4. Log Entry 3346042 Correlation coefficients between samples (Elton)
   • The correlation between samples prevent the resolution using many samples from scaling as 1/sqrt(N). The resolution flattens off at about 0.4 counts.
5. GlueX-doc-2781 (Fernando)
   • Fernando explored detailed algorithms which could be implemented in firmware
   • Conclusion is that integer averages are to be avoided and the resolution also plateaus at about 0.4 counts.
6. Discussion of data formats
   • e-mail exchanges

Number of pulses for two options

No Pulses	Full S	Full E	No Ped S	No Ped E	No Time S	No Time E
1	3	3	3	2	2	3
2	5	6	5	4	3	6
3	7	9	7	6	4	9

1. • Pros and cons discussed.
   • Beni: Note that the fine time determination is less useful for very fast signals, such as those in the tagger.
2. Any other business