Generic Digitizer for Instrumentation

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Generic Digitizer for Instrumentation

• How to replace the COMET board?

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Features of the COMET board

• VME 6U form factor
• 1MHz, 2MHz or 5MHz boards.
• 12 bit ADC, -1 or -5 Volts (not easily
  selectable).
• Four input channels, trigger/gate/enable and
  clock inputs.
• Random sampling clock capability
• Allows to feed the trigger as a clock
• 64K sampling memory
• Capable of Block Transfer (slow)
• Settings in A16 memory space and data in A24.
• Allows for stringing boards together as if they
  were one board with more channels

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More COMET

• Originally designed at Fermilab and built
  someplace else. This was a custom board built to
  suite our specific needs.
• Currently used in the FBI(2per), AGI(1), Flying
  Wire (up to 6), and IPM(16 per) systems.
• Lack of spares and replacement parts has driven
  us to explore the replacement of these boards.

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What are the requirements?

• VME 6U form factor
• 4 channels per board
• No less than a 10MHz maximum clock rate
• 16bit ADC, -2.5V, -1V, 0-5V (jumper select)
• External Clock, Gate and Trigger inputs.
• Smart triggering system
• Minimum 64K sample memory with status bits
• Allow future onboard data processing capability

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Example Sampling ModesSmart Trigger

• Inputs
• Number of Sampling cycles to complete N
• Number of Samples per cycle M
• Trigger selection (soft/hardware)
• Clock selection (external/internal)
• Gate/enable selection (soft/hardware)
• Examples
• FBI(1000 turns) (72P and 72AP samples)
• N 1000, M 144, T Hard, C Hard, G Soft
• Flying Wire (while in aperture)
• N ?, M ?, T Hard, C Hard, G Hard.
  Ignores N and M and samples all incoming triggers
  while gate is enabled
• IPM Main Injector (full memory) (once per turn)
• N ?, M ?, T Hard, C Internal(Max?), G
  Enable of Clock Event. Starts sampling on G,
  fills up memory at the rate of the Trigger.
• These would all be modes preprogrammed into the
  Digitizer and selectable by user. Many more can
  be created upon request.