# Presentation: 233797

## LCLS Event System 

- Outline
- HW Block Diagram
- Timing Requirements
- Time Lines
- EVG to EVR Data Transfer
- Beam-Synchronous Acquisition and Control
- Issues/Comments
- Status/To-Do

## HW Block Diagram

- PNET

- Existing
- Control
- System

**119MHz RF Clock**

**Trigger Delays and Pulse Widths, **
**Event Codes per Output Channel**

-  **BPM **
**IOCs**

**E****V****R**

**A**
**D**
**C**

-  **LLRF **
**IOCs**

**HW Block Diagram**

- IOC

**Master**
**EVG**

**P**
**N**
**E**
**T**

**Timing Pattern,**
**Timestamp, **
**Event Codes**

**E****V****R**

**Channel Access**

**Beam Rate, **
**Beam Path**

- Trigger

- Trigger

- 360Hz
- Fiducial

- IOC

**Down**
**stream**
**EVG**

**To Downstream**
** ****EVRs**

**Beam Rate, **
**Beam Path**

- Future
- MPS

-  **Camera **
**IOCs**

**E****V****R**

- Trigger

**EVG**
**Fan**
**Out**

- Camera

**EVG**
**Fan**
**Out**

**EVG**
**Fan**
**Out**

- RF
- Timing

- Modulator
- Triggers

- P/A Acq
- & Cntrl

## Timing Requirements

| Maximum trigger rate  | 360 Hz  |
| --- | --- |
| Clock frequency  | 119 MHz |
| Clock precision  | 20 ps |
| Coarse step size  | 8.4 ns ± 20 ps |
| Delay range | >1 sec |
| Fine step size | 20 ps |
| Max timing jitter w.r.t. clock | 2 ps rms |
| Differential error, location to location | 8 ns |
| Long term stability | 20 ps |

## Event Time Line – 120 Hz Beam

**F0**

**F1**

**F2**

**F3**

**F4**

**F5**

**F6**

**F7**

**0**

**2.8**

**5.6**

**8.3**

**11.1**

**13.9**

**16.7**

**19.4**

**360Hz Fiducial**

**Time (msec)**

**B0**

**B1**

**B2**

**Beam**

**S0**

**S1**

**S2**

**Kly Standby**

**CX0**

**CX1**

**CX2**

**BPM Calib**

**CY0**

**CY1**

**T1**

**T1a**

**T1b**

**T2**

**T2a**

**T2b**

**T3**

**Timing data for next Beam pulse**

## Event Time Line – 1 Beam Pulse (B1)

**F3**

**0**

**Fiducial**

**Time (msec)**

**B1**

**S1**

**Acq – BPM, Toriod, PMT, Camera**

**T2**

**1**

**1-b**

**1+d**

**Laser Control**

**1-a**

**Beam**

**Post-Beam Acq**

**Kly Standby**

**1+c**

**1+e**

**B2 Timing Data Received**

**Record processing (event, intr)**

**B1 Timing Data in records, waiting to be used**

## EVG-to-EVR Data Transfer (Dayle Kotturi)

## EVG-to-EVR Data Example (Dayle Kotturi)

## Trigger from Event Code (Dayle Kotturi)

## Beam-Synchronous Control: rules and algorithm for creating EVG trigger sequences on a pulse-to-pulse basis
Algorithm change on-the-fly based on user requests
Single-Shot vs continuous beam pulses – enforce minimum delay between single-shot requests
Bunch length measurement
Rate limit
Beam destination
MPS rate limit and destination requests
Send out calibration, standby, and software triggers during non-beam time slots

- Algorithm change on-the-fly based on user requests
- Single-Shot vs continuous beam pulses – enforce minimum delay between single-shot requests
- Bunch length measurement
- Rate limit
- Beam destination
- MPS rate limit and destination requests
- Send out calibration, standby, and software triggers during non-beam time slots

**Event Applications**

## Beam-Synchronous Acquisition: mechanism for users to request pulse-by-pulse acquisition across multiple IOCs:
Single-shot or multiple contiguous pulses
Include or exclude a pulse from resultant waveforms based on information in the timing pattern for that pulse
Can be implemented by either data mining of large data/timing-pattern arrays 
...or use the timing system to trigger data copy to special records based on preset conditions, requires reserve/release of special records

- Single-shot or multiple contiguous pulses
- Include or exclude a pulse from resultant waveforms based on information in the timing pattern for that pulse
- Can be implemented by either data mining of large data/timing-pattern arrays
- ...or use the timing system to trigger data copy to special records based on preset conditions, requires reserve/release of special records

**Event Applications (cont)**

## Immediate Issues/Comments

- EVG RF input divider – new circuit added to EVG
- Do we need EVR with RF recovery (EVR with clock)?  119Mhz availability throughtout?
- Fiber plant:
- Match network bulk cable where possible
- Where is single mode fiber needed?  Between fanouts?  To EVR w/RF recovery?
- How much EVR daisy-chaining can we do?
- Daisy chain vs tap to split
- No plans for redundancy
- TTL triggers – long trigger cables need design
- Not enough testing has been done
- Schedule.......

## Future Issues

- Modulator triggers on existing control system – how to rate-limit from new system
- Handling non-LCLS beams – add more beam-pulse-dependent info (ie, bunch charge) to timing pattern for IOC apps
- How to upgrade PMC-EVR firmware

## Status (Dayle Kotturi)

- Received the EVG/EVR 200 series VME hardware (which sends up to 2K data buffer)
- Received the EVR 200 series PMC module
- Adapted driver and device support to:
-  send the PNET data buffer (measured 66 μs transfer)
-  be OSI (running on mvme6100, RTEMS4.7)
-  with help from Till Straumann, Eric Bjorklund, Timo Korhonen, Jukka Pietarinen and Bob Dalesio

## Status (cont)

- Stephanie Allison and Mark Crane coming up to speed
- Test stands for HW folks not yet ready
- Rack/cable design for injector/BC1 well underway
- Procurement underway

## To-Do

- Finish PMC-EVR driver and test (share PMC-EVR and VME-EVR driver as much as possible)
- EVG sequence RAM programming at 360 Hz
- EVG rules and algorithm definition for Jan commissioning
- Add support for EVR timing pattern data records (in place well before next beam pulse)
- Jitter testing
- Interface with other subsystems needs review
- Commissioning test plan