OWG meeting 30-May-2008

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Agenda


Time/Location

1pm Fri 30-May-2008 CC F326


Announcements

Next Meeting

13-Jun-2008 1pm CC F326


New Action Items from this Meeting

Elliott will find out what must be done to satisfy the Jul-2008 "PED Deliverable" on Monitoring System Design.


Minutes

Attendees: Elliott W, David L, Beni Z, Alex S, Simon T, Carl T, Ben R, Mark I, Chris C, Ed J, Elton S, Vardan G.


IU CAN Control Plans for FCAL HV


Elliott reported on Matt's plans for the FCAL CAN-based HV control system

  • About 2800 Cockroft-Walton PMT bases, each a separate CAN device.
  • There are limits to the number of CAN devices on one CAN bus.
  • IU will set up a small CAN test control system using a PC and either a USB or PCI based CAN controller.
  • IU will determine how many devices per bus still give reasonable response times.
  • Current plan is to develop low-level software for the test system, then scale it up using the same software to a complete control system. May need more than one PC.
  • PC will act as an intelligent network device that hides all details of CAN behind it (similar to other components of our control system).
  • Will send very high-level commands to the PC, which will take care of all the details.
  • Major question: who will maintain this system over the Hall D lifetime? Will IU commit to this, or will JLab have to take this system over. If the latter, would we be better off with a commercial solution, if one exists?
  • Consensus was that Matt should give a presentation fairly early in the development process so we can determine if this approach is acceptable.


Accelerator Elog


Elliott and David L met with Theo Larrieu, author of the Accelerator elog, about whether it might be appropriate for Hall D online use.

  • Large overlap between Hall D requirements and existing features in Accelerator elog.
  • In some cases Theo was already planning to add features we want (esp. entry update capability).
  • In most other cases Theo is willing to add the missing features, or they can be easily added by Hall D.
  • This summer Theo will be working on the elog. When he is done we will implement the elog and evaluate it, then get back to him about what is lacking from out standpoint.
  • The elog is based on a relational database, and uses PHP for all web display.
  • About 60% of all entries are made by operators using TCL gui's, 40% by automated programs.


Fiber Test Stand

  • Initial purpose of the fiber test stand is to do initial testing of BCAL fibers.
  • Will use a source and stepper motor to scan the length of the fiber, readout via PMT at the end.
  • May eventually use SiPM instead of PMT.
  • Beni is about to order assorted equipment.
  • Elliott is scrounging around for electronics, DAQ, test, and computer equipment.
  • DAQ will use codaLite, same as in Simon's test setup.
  • F117 currently used by Carl Z and Brian K. They will clear out a large area next week and we will begin moving equipment in.
  • A TLD badge is currently NOT required to work in the room.
  • Not sure how the stepper motor will be controlled. Beni may write something, or may use EPICS.
  • May use AFECS software from DAQ group to coordinate control of DAQ and stepper motor.
  • Not sure where ADC and some NIM logic will come from, most other stuff identified.
  • Setup may eventually be modified to test other things, e.g. SiPM's.


Electronics Update

  • Chris reported on general progress in board designs, layouts, procurements, testing, etc.
  • Have a number of FADC250's now, testing going well.
  • Readout libraries coming along.
  • Almost ready to ship FADC250 to IU.
  • See Ben's report on TI prototype progress for many details.
  • Test shows components perform well within latency budget (800 ns for this system).
  • Manual trimming needed for each board to set fixed latency (using digital delays).
  • Much discussion on timing precision, latency, latency jitter, clock skew and jitter, board-to-board variations, sync/reset, etc.
  • Ed said they may build in latency stability monitoring via unused fibers in the fiber ribbon cable.
  • Very low bit error rate in 1 Gbps link tests.


Online Milestones

  • Some milestones on the wiki page are labeled "PED deliverable." Much discussion about what this means. Elton told us these are not the same as R&D deliverables, which are carefully tracked by DOE. PED deliverables are more like milestones on the way to completion of a project.
  • Elliott asked if what was presented at the recent System Review satisfied the PED requirements for example for "Monitoring System Design." Elton said what was presented were "concepts" rather than designs. Much discussion followed as to what was needed. Elton noted that the language comes from the construction world, where these concepts are clear. Vardan and David L noted that application of this to the software world was ambiguous and in many cases inappropriate. They noted that software design is an iterative process that continues during the "construction" phase, unlike building design, which ends before construction.
  • Elliott will talk to Elke and Elton to get clarification.
  • The first "PED deliverable" is in July for monitoring system design. The date can be pushed back if necessary, difficulty depends on details and what comes after it.