|ALS Controls Upgrade: Meeting the Needs of a Growing Facility|
Users may never notice it, but a major controls and instrumentation upgrade is underway at the ALS. Over the next four years, the controls system that runs all aspects of the synchrotron, from injection to magnets, will be decentralized and its instrumentation replaced. These improvements will coordinate with recent software upgrades to improve efficiency, beam stability, and “disaster scenario” control.
If you walk in the ALS control room today it will look a little different than just a couple of months ago. Half of the old submarine-style monolith that housed the Windows 2000 console computers has been removed to make way for a new console (below). The new system, temporarily assembled in a corner of the room, has taken over most of the operation of the accelerators. This system uses Windows7 as the desktop with large 30” monitor displays and a new physical setup that greatly improves ergonomics for the operators who man the controls 24 hours per day. The applications layer uses a blend of Windows and Linux OS programmed in C#/.NET, Matlab, and EPICS display tools.
The fact that the ALS has two very different control consoles reflects the fact that the ALS has two very different control systems running side-by-side. Within a few years of first light to users in 1993, plans were already underway to upgrade the control system. In the last 15 years many of the storage ring controls have been upgraded. However, one of the main impediments to slowly replacing the whole control system stems from the linking of high-level (operator interface) controls to the low-level (information from the individual hardware systems to the database) controls. The original ALS architecture is a large data pool where all systems report into a master central computer.
Not only did this central command computer system collect all the data for the ALS it also did much of the rendering of the control screens used by the operators. While the performance of this system for its day was remarkably good, as it ages it poses the problem that it is a potential single point of failure for the ALS and it’s very difficult to replace or repair.
For the last 1.5 years, a team from the physics and controls groups rewrote almost all the high level controls applications and commissioned them in the off hours during the September 2009 shutdown. It has been a major change for ALS operations, but hopefully most users did not notice as the upgrades were implemented. There is still more to be done, but the expected down time due to a major failure of the old control system could now be counted in days, rather than months.
This effort sets the stage for the next upgrade which is to replace the remaining low-level controls with a distributed control system. The DOE has agreed to provide the ALS $2M per year for four years to complete the upgrade. Along with new controls, the orbit stability system will get a major upgrade. This should arrive just in time to handle the smaller beams that the planned lattice (sextupole) upgrade will provide.