Controls & Instrumentation


The operation of the synchrotron is accomplished though the use of a distributed control system. This system is responsible for controlling the acceleration of the beam though the linear accelerator and booster ring, injection into the storage ring and then the operation of the storage ring. A host of support systems essential to the operation of the synchrotron are also covered by the control system, these including cooling system, a cryogenics plant and ventilation systems. The control system also implements machine protection functions, these protect equipment from possible damage due to equipment failure or operator error.

The distributed control system is based on the Experimental Physics and Industrial Control System (EPICS) that is widely used at synchrotrons and other scientific facilities throughout the world.

This system design is made up a Programmable Logic Controllers (PLC), conventional computers, industrial computers and servers.  These are monitored by Input/Output Control (IOC) computers.  These components inter-communicate over a data network using the MODBUS or Channel Access protocols. Operators interact with the control system thought the use of OPerator Interface (OPI) stations.  

Additional detailed information can be found in the CLS Control System Overview and Technical SpecificationControl System Overview and Technical Specification Each major system within the facility also have a component manual that details the functional requirements, design, implementation and operation of the system.

Major Systems

Accelerator Control System

The accelerator control system covers the operation of the Linac, BR1 and SR1 machines and the two transfer lines. Implemented with EPICS this system is responsible for overseeing the operation of these machines and protecting the equipment from damage. Telemecanique Modicon Momentum PLC equipment is used extensively for machine protection. The Cryogencis Plant, BR1 RF and SR1 RF systems are implemented using Siemens PLC equipment. VME equipment is used to implement orbit correction, and insertion device control.

Accelerator Diagnostics System

The proper setup and operation of the accelerator, booster and storage ring are depended on beam diagnostics. These diagnostics are used to determine beam intensity, position, and profile information. Additional information on beam diagnostics can be found in "Beam Loss Monitors" and in "The CLS Beam Monitor System".  On the SR1 ring this is supplemented by two diagnostic beamlines.

Timing System

In the operation of a synchrotron it is important to precisely trigger the operation of various accelerator components. This is accomplished through the timing system. Additional information on the timing system can be found in this Design Specification.

Beamline Control System

The beamline control system is responsible for protecting the beamline from damage as well as the operation of the beamline. Machine protection is implemented using Telemecanique Momentum PLC equipment. The typically beamline makes use of over fifty stepper motors that are used to position optical elements (such as mirrors) as well as the sample and detectors. The beamline motion control and data acquisition is typically implemented using VME equipment. Some detectors require more specialized custom readout systems. In addition to the beamline control and data acquisition system provided by CLS, users may chose to bring in their own end-stations that they can integrate using either EPICS interface libraries (available for Linux and Windows) or using a beamline wrapper interface.

Mechanical Services

Common mechanical services includes: technical equipment cooling, heating, ventilation, air conditioning, liquid nitrogen distribution and the electrical switch year. This equipment is typically controlled using Telemecanique Modicon Momentum PLC equipment that is integrated into EPICS.

Access Control and Interlock System

The Access Control and Interlock System (ACIS) monitors the linac hall, transfer line tunnels, booster tunnel, storage ring tunnel and beamline hutches.  Only after the appropriate area has been searched and secured does the system permit the generation of radiation in the secured area.  This system is based on dual redundant and diverse implementation using both hardwired relays/timers and a PLC system designed to IEC 61508.  CLS uses the Siemens S7/400 F PLC platform for this application.

Supplemental System

To support the design, commissioning and operation of the facility an assortment of other semi-autonomous or standalone system have also been developed. These systems cover a broad spectrum from vibration monitoring, mapping magnets to the main building automation system.  

Special Projects

Beamline Remote Access

CLS has undertaken a project with major funding from CANARIE and additional funding from CLS, Surface Science Western (at the University of Western Ontario), IBM Canada and Big Bangwidth to develop a remote access system for the CMCF, CMCF2 and VESPERS beamlines. The development team also includes the Alberta Synchrotron Institute at the University of Alberta. Additional information can be found on the Project Web Page .



EPICS is the result of a collaboration of many research institutes internationally. CLS has developed a variety of extensions to EPICS.  These are made available to other institutions as part of this collaboration. CLS runs EPICS IOC software on the RTEMS real-time operating system and Scientific Linux. These are distributed thought the facility and interconnect over Ethernet.  OPI computers are based on either MS-Windows XP or RedHat Linux.  The OPI act as the main interface between the users and the control system. Locally developed drivers are available on the Open Source webpage.

Contact Elder Matias to learn more about control and instrumentation at the Canadian Light Source.