The recent history and current state of the linac control

system

Tom Himel

Dec 1, 2010

1

Outline

• Why you need to know the history• The SLC control system• Phase I of the upgrade for LCLS

2

Why you need to know the history

• You need to know what we are upgrading from and what we could clone if we chose to.

• It helps to know why we are upgrading to see if we have chosen the right solution

3

In the beginning

• God created the heavens and the earth• …• On the eighth day (AKA early 1980’s) he

created the SLC control system. • God looked at everything he had made,

and he found it very good[1].

4[1] after hundreds of person-years of effort by descendents of those created on day five.

Block diagram of SLC control system

5

VMS host

Multibus I micro: LI00

Multibus I micro: LI30

Multibus I micro: CW01

…

CAMAC crate

…

CAMAC crate

CAMAC crate

…CAMAC crate

Video screens

SLCnet

Ser

ial

CA

MA

C

Description of SLC control system• Central host VMS system runs all high level

apps, operator consoles, and has central fast DB.

• Multibus-I micros (originally 8086 CPUs, upgraded to 386 and 486) control everything in their sector.

• Above connected with SLCnet, a proprietary polled network with cable TV as its physical media and the VMS interface as the master polling device. Ethernet was young and did not work well enough at that time. 6

Description of SLC control system• Each micro controls several CAMAC crates via a proprietary

serial CAMAC link.• Both commercial and proprietary CAMAC modules readout and

control all hardware– 32 channel autoranging ADC for thermocouples, small magnet

readout etc.– 16 channel DACs for small magnet control, profile monitor lamp

brightness etc.– 1 channel Power supply controller couple to external chassis for

analog and interlock control of large power supplies– BPM modules (several flavors)– 16 channel Programmable delay units for triggers– 32 channel digital input and output modules– 1 channel Klystron controller with 8088 CPU coupled to external

chassis (MKSU).7

Expansion to PEP-II• Mainly expanded the SLC control system with

some upgrades– New micros communicated with VMS via ethernet– New more precise power supply controllers got

digital information from the micro via bitbus• New types of functionality (longitudinal feedback

and CW RF) were implemented in EPICS• Cross-system SLC high level apps (correlation

plots, multi-knobs, configs, history plots …) were made to handle EPICS items

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LCLS• All new devices are controlled with EPICS• New high level applications were written

(mainly in Matlab) to control all the new EPICS devices and extended to control most of the old SLC linac devices

• LI20-30 linac magnets and BPMS were upgraded to EPICS hardware.

• Klystrons, timing, vacuum, analog and digital status are all still in the SLC control system.

9

Upgrading of the SLC control system• In 2008 we decided to upgrade the old control system

– Was significant source of downtime– Virtually everyone knowledgeable in VMS, FORTRAN or

CAMAC had retired or been laid-off.• Decided to do it in two phases:

– Phase I gets rid of VMS, SLCnet and the micros and is software dominated.

– Phase II replaces CAMAC with modern hardware and is hardware dominated

• Phase I is almost done• Phase II system architecture and implementation plan

is being reviewed today.10

Controls downtime causes

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Controls downtime causes• There is about an even split between

micro and CAMAC downtime.• The timing downtimes are with the old

timing system, not the EVG/EVR system.• We’ve also had significant (multi-hour)

downtimes due to SLCnet interface to the VMS computer and the old MPS system that luckily occurred during scheduled MD or maintenance and so don’t count in above statistics.

• Can’t count on luck. Need to fix. 12

Phase I upgrade block diagram

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Cmlog server

Multibus I micro: LI00

Multibus I micro: LI19

…

CAMAC crate

…

CAMAC crate

CAMAC crate

…CAMAC crate

Ethernet

Ser

ial

CA

MA

CArchiver server …

VME IOC: LI20

VME IOC: LI30

…

CAMAC crate

…

CAMAC crate

CAMAC crate

…

CAMAC crate

Ser

ial

CA

MA

C

Operator console

SLCnet

VMS host

Phase I upgrade• Add 1 VME EPICS IOC per sector

connected with new Ethernet network• Build VME serial CAMAC interface

(PSCD) that uses commercial hardware serial IO card with our firmware

• Produce all necessary CAMAC drivers, device support, EPICS DB, displays, and high level apps

• Test it all without impacting LCLS• Switch over on a maintenance day

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State at end of January 2011• Phase one upgrade will be running in LI20-30.

– VMS and SLCnet and micros will NOT be needed for LCLS– The 360 Hz timing information will be distributed via the

new EVG/EVR system, but the nanosecond level timing will still come from the old distribution and PDUs.

– Will still have CAMAC. This and timing expected to be largest contributors to controls downtime

– We will be scrambling to finish needed but not absolutely essential software tasks.

• Sectors 0-19 (and Damping rings and e+ source) will still be using SLC control system and will shortly be used to run FACET.

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