Transcript DAQ - Indico

APV Readout
Controllers DAQ
by Mikko Nykänen
Topic
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I try explain mainpoints of reading APV25-S1 chip in
DAQ
At begining I tell whole structure of DAQ, parts, main
purpose and functions
But main topic is APV chip and how we can adjust the
timing in DAQ
In APV we go through components, how much time is
spend and what we can change in registers
We also go throught little how we can change APV
settings, mainly how mode affects to DAQ
ARCS
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Parts
 Control computer, with ISA
Bus + PCMIO interface
 ARC Board
 Power +5V(1.5A) / 5V(0.15A)
 2 x FE Adapters
 2 x APV25-S1 chips
 Cables 50 pin, 2x20pin,
and 2 APV and power
cables
ARC Board
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Rate 20/40MHz
6 Channels
Resolution 8bit
Memory 8K x 8bit per channel
External (NIM) or Internal trigger (software)
Internal clock 40MHz or External up to 40MHz
Expansion port
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Clock, trigger, synchronised trigger and APV trigger
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Hybrid I/O
 6 differential voltage -> 6 APVs in one port
 50 Ohms resistance
 3 Standard Buffered I2C
 2 LVDS clock and 2 LVDS trigger lines
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Dimensions
 19” crate or Double Euro Format
ARC – Block diagram
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Trigger&Clock
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Local crystal oscillator,
software/external trigger ->
synchronised to system clock
Trigger is distributed via link or
missing clock pulses
Group 1&2
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2 groups of 3x8bit FADC
For correct sample timing >tune FADC clock 0-10x1.7ns
Data is stored in 8Kbyte RAM in
each channel
Data lenght
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Slow control
 2xI2C
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controller
LV control
 Hydrids
powered by FE boards
 On/off switch if nessacery
 Hybrid currents are monitored by third I2C
control
Address
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By using address via
PCMIO you can read or
write data in board or in
APV
Next colum tells what you
can see in address
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Status register
Write DAC/ Read RAM
Write memory/soft trigger
Write APV trigger data
Slow control
ADC clock delay
Write stop address
Write RAM data
Software
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ARC use LabView program
Userfriedly program and easy to use
But to main point in this prensentation
 DAQ
 For
timing is the ADC clocks value important
 In APV register you can also change timing by
changing latency
 But most important thing in DAQ is what is the mode
in APV
APV25 Register
In program you can change preamplifier,
sharperer, bias current and few other
values
 Latency is one of the value here
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 E.g
if you put latency to 132 you get 3.3us
delay
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Mode
 Defines
how APV behaves alltogether
Mode selection
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Basically you put value to mode and you
are happy, not quite
 Mode
number is based on 6bit number and
when you select in table what you want to
APV to do we calculate the numerical value
Mode register
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This picture is from APV user guide 2.2
So you select how the measurements are done and
then put the to mode
APV25-S1
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Analogue pipeline ASIC
Idea is to process data prior to sending it
APV chip has following parts: preamplifier,
sharper, 192 column analogue memory(buffer)
When APV collects data to buffer it can keep
history of earlier events. In one channel there is
data for last 4us period in pipeline. (25ns x192)
Sharper and preamplifier use 50ns
Main point in APV is the buffer. Data in
there does not over write we make flag
that is ready -> timing should be easy
 APV is ready to take data around every 56us
 This makes the chip dead-timeless, so
even fast it can collect events quite
efficient
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Timing
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In software you can change two values.
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is the latency in APV register(chip)
 2. is the ADC clock, is used to fine tuning DAQ
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You should keep mind that when the trigger
signal comes the DAQ starts after 70/35 clock
pulse around 1.6-0.8us
System clock 40MHz -> 25ns
Delays from cables is not taken account
Times
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ADC clock 0-17ns
 You
can change this on fly and you can seek best
position to collect data from screen
 Can be changed by moving the lever in ARCS
software
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APV register: Latency
 Here
you cant go over value 160 in settings
 Input value in APV register, latency
 Value 0 to reasonable 132, 0-3.3us delay
Few words
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We went through main points
Soon I do better one presentation/ document and there I
include more exact data and calculations
Final goal is to make manual, how to build this system
and how to use it.
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What tests does
How settings affect to results
But programs manual does this also so have to think different
approach->to maybe find a way optimace latencys and delays
Give working test setup and good manuam with it