# Presentation: 355059

## ILC Control System Topics

*John Carwardine and Frank Lenkszus*

*Contributions from: N. Arnold, B. Chase, D. Gurd, S. Simrock*

## Some control system topics

**Integrated control system**
**Remote access**
**Timing & synchronization**
- Machine protection
- Beam feedback systems
**Relational databases**
**Control system reliability**
- Standards

## Aspects of an integrated control system

**Provide a common toolkit for implementing applications in a consistent way across the entire facility.**
**Meet the needs of different types of user, including operators, system engineers, physicists, ...**
- Operator interface for facility control & monitoring
- Automation, sequencing, “slow” feedback
- Data acquisition for physics
- Archiving, retrieval, and analysis of machine data
- Physics modeling and simulation
- Save/restore of machine state
- Alarm management
- Mode control

## Control System “Standard Model”

- Commercial Instruments

- Custom Chassis/Panels

- Technical Equipment

_*EPICS Channel Access*_

_*Input-Output Controllers*_
_*(I/O to equipment, real-time applications)*_
_*(CA Servers)*_

_*Workstation-based Applications & Tools*_
_*(CA Clients)*_

_*Machine Interlocks via PLCs, relays, logic*_

- PLCs

## Scalability of existing control systems

**The ILC will have 10x more technical systems and I/O points than any existing facility.**
**Quantity of data that must be collected & archived**
- Network bandwidth issue.
- Global data management issue.
**Network traffic and effect on clients & servers**
- Broadcast approach to client-server interactions does not scale well (name-servers or gateways needed instead)
- Badly-behaved network attached devices.

## Some control system trends

**Increasing use and availability of network attached devices**
- Embedding controls interfaces into individual devices, eg one controls interface per bpm.
- Almost everything now comes with an Ethernet port and either custom software or an embedded web server.
- Increasing expectation of Plug & Play convenience.
- Streaming video distribution.
**Increasing use of commercial software packages, eg Matlab, IDL, LabView, etc**
- Control system toolkit should provide seemless integration.

## A network management strategy

**At the control system level, maintain single layer network to minimize latencies (“Standard Model”).**
**At the network level, manage geographically using smart switches with global backbone.**
**Utilize separate, parallel (and redundant) networks**
- “Clean” network for the main control system.
- “Dirty” network for plug/play network attached devices.
- Streaming video network.
- Dedicated network(s) for synchronous data (eg feedback apps).
- Gateways to isolate general users from critical networks.
**I&C group needs to establish allowable network protocols, and determine what can be hooked up to each network.**

- Integrated control system
**Remote access**
- Timing & synchronization
- Machine protection
- Beam feedback systems
- Relational databases
- Control system reliability
- Standards

## Remote access

**It is clear that experimenter tele-presence and remote collaboration will be an integral part of the ILC.**
**To what extent should we include remote access and remote operation in the baseline design for the ILC accelerator?**

- Integrated control system
- Remote access
**Timing & synchronization**
- Machine protection
- Beam feedback systems
- Relational databases
- Control system reliability
- Standards

## Timing & Synchronization

***RF Master Oscillator distribution***
***Timing fiducials, triggers, event generation***
***Real-time data link***
**Must be considered as an integrated system**
- Responsibilities & interfaces with other ILC working groups?
**What signals are required, and with what precision/resolution?**
**Reliability and availability**
- Single point of failure: redundant system?
- Built-in diagnostics

## Distributed RF references

**Required precision and the scale of ILC are major challenges.**
**Globally distributed references**
- RF Master Oscillator: 1300MHz
*Active phase stabilization*
- Sync pulses: 5Hz
*Must be phased to account for propagation delays.*
- Star distributed to local timing reference generators
**Locally derived references**
- Damping ring RF (eg 650MHz)
- PC gun laser (54MHz?)
- Bunch clock (3MHz)

## Grades of timing system precision

**All timing triggers derived from RF references.**
**Pico-second precision is not required for all signals. Take graded approach to reduce cost.**
**Grades of hardware trigger**
- High precision (pico-second): gun, kickers, bpms, detectors, etc
- Medium precision (nano-second): septum, modulators, etc
- Low precision / event system (micro-second)
**Software synchronization**
- Trigger software events, eg data collection

- Integrated control system
- Remote access
- Timing & synchronization
**Machine protection**
**Beam feedback systems**
- Relational databases
- Control system reliability
- Standards

- Integrated control system
- Remote access
- Timing & synchronization
- Machine protection
- Beam feedback systems
**Relational databases**
- Control system reliability
- Standards

## Relational databases

**Relational databases need to be established as an integral part of the project from an early stage**
- Initially will provide common source of parameters and component data for modeling and simulation.
- Later will become a comprehensive database of technical information for the entire facility.
**Relational database contents**
- Accelerator parameters & components
- Technical equipment and system interconnects
- Control process points

## All entities are inter-related ...

- Modeling & simulation

- Physics & machine parameters

- Integrated control system
- Remote access
- Timing & synchronization
- Machine protection
- Beam feedback systems
- Relational databases
**Control system reliability**
- Standards

## What do we mean by highly reliable?

**Mitigation should depend on the consequence of failure**
- Control system failure resulting in loss of beam.
- Control system failure resulting in something bad happening.
**Field experience shows that most controls failures are due to power supplies and cooling failures or power cycling.**
**Only have to be highly reliable during scheduled beam time**
- Take advantage of scheduled down time for preventative maintenance and pre-run testing.
- Equipment diagnostics can help detect and prevent impending failures. Diagnostics need to be built in.

## What do we mean by redundant systems?

**Hot spares that can be remotely swapped in when something fails to reduce beam downtime.**
**Automatic fail-over to prevent downtime or equipment failure**
- How fast? Bump-less? At the I/O point level?
- Implies the failure can be detected in a suitable timeframe.
**Hot spares could be maintained in an active state (but not attached) to ensure they are functional when needed.**

## Closing remarks

**We are in a new era of building large-scale facilities through international collaborations of many institutions.**
**The control system must work with (and for) everyone.**
**It is important that we have agreement on responsibilities and interfaces between working groups.**
**The project will benefit tremendously from early setup of relational databases for accelerator and technical data.**
**Establishing and enforcing facility-wide controls & network protocols for all equipment will be essential.**