OWG meeting 14-Mar-2008

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Agenda

  • Announcements
  • Review of minutes from 29-Feb-2008 meeting
  • Status report on online-related R&D and PED work not covered below - various people
  • Introduction to Allen-Bradley PLC's (media:Lassiter-PLC.ppt)- Steve Lassiter
  • Latest trigger drawings - Chris C.
  • Other electronics issues - Fernando B.
    • Trigger System Diagrams
    • Signal Distribution (Global, VXS, Clock, Trigger, etc.)
    • Signal Distribution (SD) Module
    • Trigger Interface (TI) Module
    • Energy Sum (ES) Module
    • Energy Sum Processor (ESP)
    • SubSystem Processor (SSP)
    • Tagger Energy Processor (TEP)
    • Global Trigger Processor (GTP)
    • Track Subsystem Processor (TSP)
    • Global Trigger Crate
    • Software Support & CODA
    • Test Strategies


Time/Location

1pm Fri 14-Mar-2008 CC F326


Announcements

Next Meeting

Fri 28-mar-2008 2pm CC F326


New Action Items from this Meeting

Minutes

Attendees: Fernando B, Ed J, Alex S, Carl T, Vardan G, Dave A, Elke A, Dave D, Ben R, Elliott W.


PED and R&D

  • Dave A mentioned that the DAQ group is collecting documentation on a number of items. Graham will present the latest on the EMU (Event Management Unit, in this case the event builder) a the next OWG meeting.
  • Much of the meeting was devoted to progress on trigger and electronics, see below.


PLC's in Hall C and Hall D

Steve Lassiter is an engineer working in the Physics Division on controls systems using PLC's. He helped set up the Hall C magnet power supply PLC (the Hall D magnet power supply is identical to the Hall C supply):

  • PLC's can be programmed in a number of languages: ladder logic, function block, C, Basic, etc.
    • Programs are sequential and prioritized.
    • Function blocks can have many parameters.
    • Can reprogram on the fly.
  • Inputs can be voltages, currents, on/off states, ethernet, RS232, etc.
  • A-B specific hot-swappable I/O modules can live in chassis's in 19" racks.
  • Enormous range of field devices from many manufacturers connect to A-B modules.
  • Many ways to talk to PLC: Ethernet, OPC, DeviceNet, ControlNet, etc.
  • Once PLC removed from Hall C, no failures in 2-3 years of operation.
  • Signal cables can be very long, > 500 feet.
  • HMI (Human Machine Interface) is A-B supplied GUI builder, Windows only.
    • security features
    • web capability
    • Epics access possible
    • automatic alarming, page, call, etc.
    • uses FactoryTalk protocol via Windows server
    • can interface to database
    • need client licenses to run RSView gui on Windows
  • Hall C uses dual-redundant hot-swappable CPU in PLC.
  • Upload new program on-the-fly easy, drag-and-drop programming simple, high reliability.
  • Can work from home.
  • Can enable trending displays, keystroke logging, EPICS compatibility.
  • About six A-B PLC's on site (Cryo, not Accel).
  • PLC not replacement for safety systems.
  • Chose A-B over Mitsubishi and Siemans many years ago for technical reasons (reevaluate?).
  • Steve showed tentative control drawings for Hall D magnet, created a number of years ago by a contractor.


Trigger and Electronics

It was agreed that notices for ALL electronics meetings will be sent to the halld-electronics mail list. Minutes from all electronics meetings will be posted to the Wiki (under Electronics):

  • Fernando reported on a local "Trigger Workshop" held last week.
    • almost complete trigger drawings were shown
    • VXS is choice for all crates for now (less manpower than ATCA)
    • all systems are 10**8 compatible
    • how many GTP's are needed? how many physics triggers needed? how many calibration triggers?
  • Meeting w/Gerard settled many VXS issues concerning 72-channel 125 MS/s FADC board.
    • Need 2 ns resolution, not demonstrated yet (Simon's best is 3.7 ns)
  • Inner straw rate around 50 kHz.
  • Need GS/s sampling of CDC and FDC pulses for analysis.


Trigger Distribution Board

  • Ben showed specs for the trigger distribution board.
  • Trigger distribution crate will hold TS, TF, and TD boards, can trigger maximum of 128 crates.
  • Need prototype of trigger distribution system - a few weeks from now?
  • Will use I2C to query all boards.