SLC-Aware meeting notes from March
25, 2004
Present: Most of SW group + Steph, Dayle, Bob D., Patrick K.
Agenda:
Check back on previous homework
Discuss more functional requirements
Prepare next cycle of work
1) Question on best location for code
Ed reported on his idea to do the Message to IOC translation on VMS and use
Channel Access to drive the IOC. He felt the VMS work would be easier than on
vxWorks and since we'll be providing a channel access method of control as well
we might as well just use that.
Spencer, among others, wants to avoid doing VMS work where possible.
Ron relayed a thought from Mark Crane about putting this transformation in the
proxy server, using XML as the proxy <-> IOC communication.
The difficulty of testing and single point failure mode were pointed out by
Ken U.
So, for now, we are still assuming that the code goes in the IOCs.
2) BPM information
Patrick K reported that current plans forsee replacing ALL BPM processing with
new VME BPM processors. This means that the linac SLC-aware IOCs will have to
faithfully fulfill ALL current BPM functions.
The injection line BPM support at the beginning may be able to be uni-functional,
but full BPM support is required.
3) Feedback information
Patrick reported that LCLS will require the full fast feedback mechanisms (including
cascaded feedback) in the linac. Karey says the "VMS bounce" path
provides only slow response and otherwise only KISNET is in place. For SLC-aware
IOCs to work as currently implemented fast feedback micros, an ethernet connection
will have to work.
Steph reports that Til has a 4kHz feedback running on an IOC. We might profit
by looking at the communication there.
4) Timing system considerations
Tony answered questions about timing synchronization, pulse IDs, regional beam
codes, etc. Tony also sent out E-mail with overview documentation later.
Next Steps:
A list of message codes with a short description of the actions they control
is needed next. This includes DBEX, TIMEX, Magnet, and BPM messages, for starters.
I will meet later with Mike Z, Ken U, and Tony to figure out how best to organize
this information and who might find time to do it.
I expect to see Bob again back here in two weeks again. If possible, we should
have more data available and be able to get an idea of the complexity of the
work required.
/Ron