1. Laboratorio per dottorandi 2017 Particle Accelerators Control System
M. Bellaveglia, S. Pioli
INFN - LNF

2. Introduction Aim of a control system
Remotely control all the devices in a system
Local interface with devices using low level drivers
Provide a simple Graphic User Interface (GUI)
Automatically generate a log of the system status

3. Control system architecture
In modern accelerator control system the architecture is multilayer
Typically there are three main layers:
Presentation layer
All the end-user program that constitutes the operator interface in the control room
Application layer
Database, data (and command) server, machine protection system (MPS), system applications
Resource layer
Device controllers
Layer are embedded in a high speed network

4. Control system architecture
High Speed Network
Control system architecture
Presentation Layer
Control Room
Applications
Automated Measurements
Application Layer
Data Server & Log
Database
MPS
System applications
Resource Layer
Device
Controller #1
Device
Controller #2
Device
Controller #N
Accelerator Devices and Equipment

5. Resource Layer
Low level driver are used to connect single devices to the controllers
Local buses can be used to connect the devices (canOpen, serial, ethernet, USB, …)
Controllers share on the network the data about every single device

6. Resource layer – Virtual objects
Typically each device (or group of devices) is represented in the control system as a virtual object with attributes:
Static (initialized at the startup), read-only
IP address, channels in I/O cards, location,…
Dynamic (continuous refresh)
Read-only
Vacuum level, RF amp/phase monitor, motor abs. encoder
Read & write (can be set by a command)
ON/OFF status, camera gain, RF feedback set points
Virtual objects are accessible at any layer. Their attributes are shared on the network

7. Application Layer Data server & log: Database
Can be used to share the virtual objects on the network continuously reading their attributes from controllers
Stores the important attributes at definite time intervals (dta logging)
Stores the beam measurement data
Database
stores all the static information (how the machine is constituted in terms of virtual objects)

8. Application Layer MPS (Machine Protection System) System applications:
Acquire all the necessary data from the virtual objects and generates real-time interlocks
Vacuum level, radiation level, sub-system malfunctioning trigger RF (beam) shut down
System applications:
Applications that run in a dedicated server
Beam measurement data elaboration
Virtual machines for controller startup

9. Presentation Layer
All the panels that operators need to make the accelerator work
This layer uses the virtual object structure, but it is transparent to the operator
The operator doesn’t need to know how the devices are controlled or even which device is controlled
He is trained to use the GUIs that have to be simple and reliable

10. Examples – SPARC vacuum ion pumps
Pump and controller

11. Examples – SPARC vacuum ion pumps
Virtual object

12. Examples – SPARC vacuum ion pumps
Presentation layer panel

13. Example – EPICS Experimental Physics and Industrial Control System
Input/Output controllers (IOC)
With EPICS, the device attributes (Process Variables) are accessed directly knowing their names
Channel Access (CA) applications

14. Example – EPICS Experimental Physics and Industrial Control System
Once IOCs are set up, the PV (process variables) are available on the network
CA applications can be written using some simple libraries provided by EPICS developers.
Also many programming languages have CA libraries available(Matlab, Python, LabVIEW,…)
The presentation layer applications can be then programmed using many visual languages capable to display the information

15. Example – EPICS Experimental Physics and Industrial Control System
SPARC control room application to control the C band RF chain

16. Example – EPICS Experimental Physics and Industrial Control System
CA get

17. Example – EPICS Experimental Physics and Industrial Control System
CA put

18. Thank you