Managed by UT-Battelle for the Department of Energy SCL Vacuum Control System Upgrade Derrick Williams

2Managed by UT-Battelle for the Department of Energy Presentation_name Design Scope of the SCL Vacuum Upgrade Upgrade the Super Conducting Linac (SCL) Vacuum System to a PLC Control System. 1.INCREASE RELIABLITY: Reduce the number of control components!  Old configuration: Custom built chassis, Two Beckhoff I/O stations, External “AND/OR” Gate Relays and Hytec serial control per vacuum rack.  New configuration: One PLC and one Digi PortServer for serial control per vacuum rack. 2.REDUCE DOWN TIME: The Original custom boards are not hot swappable; chassis has to be powered off and that means RF on 4 cryo modules will be off during this time. PLC allows by-passes installed via software and logic changes can be made on the fly. New chassis has easy access to troubleshoot I/O. The new serial interface will not require the IOC to be rebooted on regular intervals. 3.AVAILABLITY OF SPARES: All custom built hardware will be replaced with standard PLC and off-the-shelf components. Serial communication hardware: Hytec (UK built hardware) replaced with Digi PortServers. 4.CONTROL SYSTEM FLEXIBILITY: PLC code is easily changed and hardware can be expanded for future modifications.

3Managed by UT-Battelle for the Department of Energy Presentation_name Design Effort 1.Hardware: PLC system with PLC chassis to interface with existing field cable infrastructure; Digi solution for serial control; fast valve controller to use existing field cables and interface with PLC system 2.Software: IOC and PLC code development, Digi serial control, and operator screens 3.Documentation: Develop test plans for new PLC vacuum control system for each cryomodule & warm section. Create design drawings for PLC interface chassis and field wiring

4Managed by UT-Battelle for the Department of Energy Challenges to upgrading any control system in a short maintenance window 1.Maintain the design integrity for protecting the equipment.  New design must meet or exceed the original design criteria  Detail test procedures must be written before installation and completed before returning system to operations. 2.Be as transparent to operations as possible  The upgrade needs to fit in the outage window as not to impact the facility’s run schedule. Presentation_name

5Managed by UT-Battelle for the Department of Energy PLC Response Time for Interlocks Presentation_name The time for the MKS controller to respond to a vacuum increase above the relay setpoint and output a signal to the PLC is ~13 msec. By using a periodic task with a scan rate of 2 msec and by limiting the amount of logic in that task, the Allen-Bradley 1756-L62 processor response time is less than 2 msec. Also, the scan rate for the digital input module has to be set at a fast scan rate to achieve the desired PLC response time. The overall response time for a vacuum pressure to increase above the interlock limit and for the PLC to output a 24VDC signal to the LLRF system to turn off RF power to a cavity is ~15 msec At SNS it is required that RF power to a cavity be turned off within 16 msec of a vacuum excursion (typically due to an arc). The MKS gauge controller provides an analog pressure reading and a relay digital output that can be used to sense pressure exceeding a threshold. The PLC uses both signals to interlock the RF power to a cavity. However the analog signal is processed much slower than the relay digital input.

6Managed by UT-Battelle for the Department of Energy The SCL Vacuum System was broken down into 8 sections Picture is 1 of 8 vacuum racks for SCL Vacuum System. SNS uses the MKS 937A gauge controller and Varian dual ion pump controller. Presentation_name Original vacuum rack with J- lab equipment.

7Managed by UT-Battelle for the Department of Energy Presentation_name PLC 3….8 Digi PortServer SCL Vacuum Block Diagram PLC Interface End Chassis ION Pump Controller Gauge Controller SCL_Vac:PLC2 ION Pump Controller Gauge Controller SCL_Vac:PLC1 CM-1 CM-2 CM-3 CM-4 CM-5 CM-6CM-7 CM-8 …. Zone 1Zone 2 Zone Field Devices PLC Interface Middle Chassis Field Devices SCL_Vac:IOC Ethernet Digi PortServer LEDP Fast Valve Controller Repeats for Zones New Components

8Managed by UT-Battelle for the Department of Energy EPICS Screen Shot for LEDP & CM1 Presentation_name

9Managed by UT-Battelle for the Department of Energy Presentation_name Upgrade Changes Before and After Front View Installation Photos Beckhoff I/O Custom Hardware Custom Power Supply Before After A/B PLC PLC Interface Chassis Auto transfer switch for AC power.

10Managed by UT-Battelle for the Department of Energy Presentation_name Upgrade Changes Before and After Rear View Installation Photos Custom Hardware Beckhoff I/O “AND” Gates for LLRF Interlocks Custom Power Supply Before Digi PortServer PLC Interface Chassis 24V Power Supply PLC Output for LLRF Interlocks After

11Managed by UT-Battelle for the Department of Energy Presentation_name New Hardware is COTS Allen-Bradley PLC PLC interface chassis; all parts are COTS VAT fast valve controller Digi Portserver 16 configurable ports for RS-232 and RS-485 All the new hardware is readily available and commercial off-the-shelf (COTS) All materials were staged up for each vacuum rack before the upgrade started!

12Managed by UT-Battelle for the Department of Energy Presentation_name Important to Plan and Test ! 1.It’s very important to include lab test time in your cost estimates as well as the schedule. 2.Don’t try to install more than possible in an outage window. The first system installation will have some learning curves. 3.We only upgraded 1 system to validate the design and installation plan on the first outage. Then we were able to install 2 and 3 systems during an outage. 4.We were able to install 1 vacuum rack upgrade and have the system controlling through EPICS in 1 day. The interlock procedures would take several days to complete. DateZoneCryomodulesInstallation Status Feb Complete Jul Complete Jul Complete Oct Lab Tested Jan next to be installed Jan next to be installed Aug Aug-097Dummy Aug-098Dummy 28-32, LEDP

13Managed by UT-Battelle for the Department of Energy Presentation_name Keys for a Successful Upgrade  Plan, plan, plan, test, test, test! 1.Cost and schedule not only the installation portions, put include lab testing, procedure writing, etc. It’s often overlooked and it adds up more than you think! 2.We were able to mockup a vacuum rack in the lab to test every I/O point, PLC logic, and EPICS screen. This is also a good opportunity to walk thru the test procedure.  Transparent to Operations 1.Break large systems down into manageable sections to fit in the outage window. The upgrade should not impact the operations of the facility if possible.  Documentation 1.Test procedure are critical and every combination of the systems interlocks and logic needs to be included. If it’s not written down you will overlook it! 2.As-built drawings and finalized procedure versions soon after installation is complete.