SNS Integrated Control System
SNS Timing MasterLA-UR-03-3377
Eric Bjorklund
SNS Integrated Control System
Basic Characteristics
Event System.– 256 events possible. 25 events currently in use.
~5 millisecond machine cycle. 60 Hz.– Option to go to 120 Hz. when second target added.
10 second super-cycle.
Clock synchronized with ring RF.– Ring RF is 1.057767 Mz at 1 GeV– Clock is 32 X Ring RF
SNS Integrated Control System
Timing System Components
Ring RF
TimingReferenceGenerator
NeutronChoppers
ACLine
SNS EventLink
Master
X32 PLL(33 MHz)
SNS RealTime Data
LinkMaster
10 MHzCrystal
Osc.
TimingSlave
(V124S)
MachineProtection
System
ICS IOC'sSNS Utility
Module
LEBTChopper
*4 PLL(64 MHz)
ExperimentalHalls
Diagnostics
RTDLEventLink
MasterTiming IOC
GPS
SNS Time StampsBeam data
RF GatesExtraction KickersTxHV Gates
High resolution timestampsMachine Modes
SNS TimestampsRemote ResetSynchronous ISR’s
Beam DelayBeam PhaseMicro pulse widthMacro pulse width
SNS Time stampsDelaysGatesTriggers
Timing SystemHardware
Timing System Users Experimental Systems
Subsystem Hardware
SNS Integrated Control System
Two Transmission Links
Event Link– Transmits the timing events that define a machine cycle.– Each event is 8 bits plus parity (256 events maximum).– Clock is variable and derived from the ring revolution
frequency (32 * Frev).– Events 0 – 63 are generated by the timing system hardware.– Events 64 – 255 are generated by software (no fixed times).
Real-Time Data Link (RTDL)– Transmits machine parameters and data prior to every new
cycle.– 128 frames possible (expandable to 255).– Each frame contains an 8-bit frame number, 24-bits of data,
and an 8-bit CRC.– Clock is 10 MHz.
SNS Integrated Control System
Sample RTDL Data Frames
Frame Number Data
1 – 3 Time of day
4 Event link period
5 MPS mode
6 60 Hz phase error
7 Beam Width
15 IOC Reset Address
17 Pulse Flavor
18-21 RF Gate Widths
24 Previous Pulse Status
25 Cycle
255 24-bit CRC (calculated)
SNS Integrated Control System
Timing Master Crate Layout
Processor
Utility M
odule
Event Link M
aster (V123S
)
Event Link Input M
odule (V101S
)
Event Link Input M
odule (V101S
)
Event Link Input M
odule (V101S
)
Event Link Input M
odule (V101S
)
Line Synch M
odule
(Reserved)
Trigger M
odule (V124S
)
Trigger M
odule (V124S
)
Trigger M
odule (V124S
)
Trigger M
odule (V124S
)
Trigger M
odule (V124S
)
Trigger M
odule (V124S
)
Trigger M
odule (V124S
)
Trigger M
odule (V124S
)
Frequency C
ounter
Event M
onitor
VM
E B
ridge
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
VM
E B
ridge
Utility M
odule
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
(Reserved)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
RT
DL Input M
odule (V206S
)
GP
S Interface
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
RT
DL Input M
odule (V206S
)
RT
DL M
aster (V105S
)
SNS Integrated Control System
Event Link Generator Hardware
Event Link Master Module (V123S)– VME Module.– Generates event link carrier (~17 Mhz).– Accepts, prioritizes, and transmits “hardware” and “software”
events.
Event Link Input Module (V101S)– VME Module for generating “hardware” events.– Communicates with the event link master module over the
VME P2 backplane.– Hardware events generated from TTL inputs to the V101S– 16 events per module.
SNS Integrated Control System
RTDL Generator Hardware
RTDL Master Module (V105S)– VME Module– Generates the 10 MHz RTDL Carrier Signal and the RTDL
frames.
RTDL Input Module (V206S)– VME Module. 8 frames per module.– Stores the data frames to be sent each cycle on the RTDL.– Communicates with the RTDL master module over the VME
P2 backplane.
SNS Integrated Control System
Additional Modules
Timing Reference Generator– Double-Wide VME module.– Provides the 60 Hz “Cycle-Start” signal to the event link
master module (V123S).– Uses a PLL to track the AC line zero-crossing and “smooth
out” power grid frequency fluctuations.– Resolves the “conflict of interest” between power supplies
that need to be “line locked” and the neutron choppers’ need for stable timing.
Frequency Counter– VME Module in the Timing Master crate.– Used to monitor the frequency of the event link clock.– Frequency is broadcast on the RTDL and sent to the timing
reference generator to compensate for changes in the ring revolution frequency.
SNS Integrated Control System
Additional Modules
GPS and GPS Interface Module– GPS provides time source and NTP time service to the site
computers.– VME interface card captures the GPS time at each “Cycle
Start” time.– Captured time is sent out on the RTDL.
Event Link Monitor– Monitors the event link and records which events occurred
and when.– Buffers one full “Super-Cycle” (10 seconds).– Used by the event-link part of the time line monitor to make
sure the event link is correct.
SNS Integrated Control System
Real-TimeData Link
(RTDL)
ExtractMPS FPAR
EventLink
End Injection
Machine Cycle Timeline
0 2 ms1 ms 6 ms4 ms 7 ms5 ms 8 ms3 ms
AnytimeAnytime
Informational Events, non critical timingTime Critical Events, (soft events disabled)
RTDLTransmit
Snapshot, 1Hz, 6Hz,
etc… RTDL Valid
RTDL parameter transmission
(for next cycle)
RF & High Voltage Events
MPS FPL
System xxx Trigger Events
(Alternate) Cycle Start
Machine
+60 Hz ZeroCrossing
-60 Hz ZeroCrossing
Line-SynchReference
Clock
Beam OnCycle Start
Mostly Stable Triggers Beam On Range
Allowed Range for Variable Triggers
Extraction Kicker Charge
beam accumulation
SNS Integrated Control System
The Product and the Perpetrators