Revision as of 16:14, 22 November 2016

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Documentation

DAQ

• VME Crate Diagram
• VME Crate Modules
  • FlexIO Board
  • Scaler Module V560 (pdf)
  • CAEN QDC V792 (pdf)
• Connection Diagram
• Signal Connections

FADC Documentation

• Hardware Architecture (pdf presentation)
• Firmware Architecture part1 (pdf)
• Firmware Architecture part2 (pdf)
• Data Format (pdf)

CODA Startup

• FADC CODA is running on hamoller computer under moller account.

To start CODA one can type command:
start_coda_fadc - that fires up the usual set of windows for ET, ER, EB, etc.
For FADC DAQ fadc_moller configuration in CODA RunControl is used.

• FADC parameters.

There is configuration file with settable parameters for FADC.
File is located in directory: ~moller/crl/FADC/fadc_params.cnf
Parameters from file are loaded to FADC in Prestart state of CODA.

There is self explained list of FADC parameters from configuration file:

# Wed Apr 21 16:22:20 EDT 2010
# FADC settable parameters

# Threshold on calorimeter sums (define triggers and SW scaler logic)
FA_SUM_THRESH_CR 8500
FA_SUM_THRESH_CL 8500

# Threshold on individual channels
# Define SW scaler logic for Scintillators only
# Controls digitized data output for all channels (ie. 'zero-suppression')
FA_CHN_THRESH_SR 500
FA_CHN_THRESH_SL 500
FA_CHN_THRESH_CR 500
FA_CHN_THRESH_CL 500

## Prescale range: 1--2047
FADC_PRESCALE_CL 1000
FADC_PRESCALE_CR 1000
FADC_PRESCALE_CRL 200
## These many DATA trigger are grouped into each DATA interrupt
FADC_EVENTS_PER_BLOCK 20

## PULSE_WIDTH range is from 3--255 (3 is default)
FADC_PULSE_WIDTH 3

## COIN_WIDTH range is from 1--255 (2 is default)
FADC_COIN_WINDOW 2

## Delays range: 1--255
FADC_DELAY_CL 0
FADC_DELAY_CR 0
FADC_DELAY_SL_0 1
FADC_DELAY_SL_1 1
FADC_DELAY_SL_2 1
FADC_DELAY_SL_3 1
FADC_DELAY_SR_0 1
FADC_DELAY_SR_1 1
FADC_DELAY_SR_2 1
FADC_DELAY_SR_3 1
## This delay is for the _delay counts (random background measure)
FADC_DELAY_SRL 25

• Data stored on hamoller computer to directory: /data1/raw/

Analysis

• Start ROOT-based analizer
• Data Trigger Analysis

Useful tips

• Signal photos: MPS(blue) vs Helicity(yellow) signal, zoomed , as on Oct 07 2012

Known Issues and Firmware upgrade

• Known FADC issues*
• FADC dead time

• • Bottom line:

 - The FADC _DATA_ triggers have an intrinsic 100--150ns associated deadtime.
   - We measure gap from 0 to 150ns in the Poisson distributed
     time-between-triggers for production data.  Ed J. can account for 90--100ns
     of that as described below.  We're not sure where the remaining 50ns is coming
     from, but I don't think we care at that level.

 - The FADC scaler data (ie. HELicity triggers) do /not/ have this deadtime.

• Details are here

• Plan for upgrade
• FADC firmware upgrading

  We considering the possibility to have more counters array and programable logic 
  unit (PLU) on the board of FADC  to programming a single channel coincidence 
  and counting it on the scalers.

  For example:
     sumLS.and.CL2.and.CR2,
     sumLS.and.CL2.and.sumCR, ...  and so on.

  The module type of  LeCroy-2365 can be used as prototype for this PLU.

• Preliminary PLU parameters:

     16 inputs by 8 outputs, with possibility to provide the connection 
     of any inputs to any output through the logic function of
     (OR), (AND) for inputs and function (NOT) for outputs.
     

• The programmable registers array(read/write):

      8 registers ( 16 bit) for AND function (every bit is corresponded to one input, 
                            the register number is corresponded to the output number), 
      8 registers ( 16 bit) for OR function (every bit is corresponded to one input, 
                            the register number is corresponded to the output number)
      one (8 bit) register for NOT function of output (every bit is corresponded to one output).
      

• Scalers array:

     8 channel of 32bit counters connected to the corresponded outputs of the PLU.

• Add the possibility to disable generation of "Data trigger" at all and enable only trigger from helicity.

Literature

• FADC for Hall A Moller (March 18, 2009)
• Moller FADC DAQ Upgrade