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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