LCLS Controls: Architecture
Historic Meeting Schedule 2004
- Nov.2: Overview of the SCP
Patrick Krejcik presented an overview of the SCP as it's used by MCC operators. The purpose of this meeting was to become more familiar with the functions that we will need to provide via EPICS and modelling software (XAL, Matlab) if we someday want to retire the SCP.
It would be nice to leave this meeting with a prioritized list of the applications we intend to implement. (This didn't really happen but we all did get more familiar with scope of the the SCP). This is also a good place to start for identifying the subsystem requirements you may still be gathering :)
- Nov.9: RTEMS Tutorial
Till Straumann presented a tutorial showing enough info to get up and running with RTEMS: how to build, install and an overview of useful commands. For Josh, we used VNC (a Mac-anywhere tool) shared application to see Till's presentation. Notes: Bob at SLAC
Links of interest:
EPICS May 2004 Collaboration Meeting RTEMS presentation
Link to RTEMS at SLAC
Link to RTEMS homepage
ICALEPCS 2001 RTEMS Overview paper
- Nov.16: Modelling Details
Where are we going with modelling? What will LCLS do on day 1, on day 1+5yrs? We have the choices of SCP s/w, Matlab and XAL so far. What about the underlying RDB? Is this Oracle? By when is this needed?
Mark Woodley, Greg White and Linda Hendrickson will present their views on how LCLS should do modelling for 10 minutes each and then there will be a follow-up group discussion.
Link to Greg's presentation:
LCLS Nominal Technologies
Link to Patrick's list:
LCLS Controls Software - Requirements for High-Level Applications Packages
- Nov.23: The Future of Timing System
Right now we are saying we want the homegrown PNET board interfacing to SLAC MPG and then the SLS EVG and EVR doing the rest. But are there new requirements where LCLS needs to be able to send additional triggers out? For eg, we are designing to run operationally at 120 Hz (where we choose 1 "slot" of 360 Hz Main Drive Line (MDL) fiducial), but is there a need to run the Injector at 10 Hz simultaneously? Are there other rqmts like this for additional triggers to be output from the EVG?
(From LJH) Consider the slice emittance appplication: (assume EPICS app, not via the SCP) the user will need to request a new one-shot measurement of the profile monitor; Patrick believes this needs a single user-requested trigger. Furthermore, he may want the rf deflecting cavity to trigger at a subset of the beam rate, such as 10 hz.
(From LJH) Consider the example of dithering feedback: (Dithering is where we move the phase up and down by a small amount and get a slope or parabolic fit, to optimize a 2nd order problem). I think a good implementation of this is synchronized by the timing system (so the fast dithering feedback would be dependent upon programmed PNET bit patterns which could be read out by the feedback system).
There are two types of triggers going out: "absolute time" triggers passed through from MDL (eg. for RF) and "relative time" triggers which originate at EVG.
Within a single period (1/120 Hz or 1/10 Hz, etc), what interrupts have to go out? Are some more time-critical than others?
What else do we want the EVG to fan out in the status info? Health of last beam pulse, for eg.?
The above approach implies we will use the MPG forever. What should our long term plan be for this?
There are links to timing system documents at:
LCLS Timing System (see Inputs to Functional Requirements and Design section)
- Nov.30: NEW TOPIC: HVAC signals from Conventional Facilities needed to monitor by LCLS Control System. The inputs are design binders from Jacobs engineering, so unfortunately I have no inputs for remote attendees.
POSTPONED UNTIL LATER DATE: Early design layout of possibilities for new "Day2" online modelling software Initially, on "Day 1" of LCLS Operations, we'll use the SCP online model, but "Day 2" implies the day when the new applications (that don't exist on the SCP) are needed.
Linda/Greg/Patrick/Mark to present the options.
- Dec.7: Cancelled due to EPICS Collaboration Meeting
- Dec.14: Postponed: Power Supply Controls
Kristi will present the status of the magnet power supply controls software.
- Dec.21: Lab is closed. Happy Holidays!
Meeting Schedule 2005
- Jan.4: The new LCLS Injector PPS:
Patrick Bong presented the work done to date on the LCLS PPS and an overview of its integration with the LCLS controls system. Link to presentation:
LCLS Personnel Protection System
- Jan.11: Postponed due to EPICS class: BPM communication path details
What is the communication path for the options being evaluated? How does the Libera BPM control module compare to Echotek? Group discussion to draw block diagrams of the two options for comparison and contrast.
Meeting MinutesMinutes in date order
Contact: Dayle Kotturi
Last Modified: May 13, 2005