The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.
TY - CONF AU - Baker, K.V.L. ED - White, Karen S. ED - Brown, Kevin A. ED - Dyer, Philip S. ED - Schaa, Volker RW TI - Interrupting a State Machine J2 - Proc. of ICALEPCS2019, New York, NY, USA, 05-11 October 2019 CY - New York, NY, USA T2 - International Conference on Accelerator and Large Experimental Physics Control Systems T3 - 17 LA - english AB - At the ISIS Pulsed Neutron and Muon Source we talk to a variety of types of beamline systems for controlling the environment of samples under investigation. A state machine is an excellent way of controlling a system which has a finite number of states, a predetermined set of transitions, and known events for initiating a transition. But what happens when you want to interrupt that flow? An excellent example of this kind of system could be a field ramp for a magnet, this will start in a "stable" state, the "ramp to target field" event will occur, and it will transition into a state of "ramping". When the field is at the target value, it returns to a "stable" state. Depending on the ramp rate and difference between the current field and the target field this process could take a long time. If you put the wrong field value in, or something else happens external to the state machine, you may want to pause or abort the system whilst it is running. You will want to interrupt the flow through the states. This presentation will detail a solution for such an interruptible system within the EPICS framework. PB - JACoW Publishing CP - Geneva, Switzerland SP - 219 EP - 222 KW - target KW - controls KW - EPICS KW - LabView KW - electronics DA - 2020/08 PY - 2020 SN - 2226-0358 SN - 978-3-95450-209-7 DO - doi:10.18429/JACoW-ICALEPCS2019-MOPHA012 UR - https://jacow.org/icalepcs2019/papers/mopha012.pdf ER -