Objectives
This module introduces the RTBSA GUI. After completing this module, an operator should be able to:
- Plot and interpret a signal vs. time
- Plot and interpret two signals against each other
- Plot and interpret the Fast Fourier Transform (FFT) of a signal
- Tune a signal using the plots (either visually or using linear/polynomial fit)
- Use the standard deviation filter
Introduction
Beam Synchronous Process Variables (PVs) are signals that are tied to the beam pulse that generated them. RTBSA uses this feature to build a pulse by pulse "picture" of the beam so that we can see correlations between signals that would otherwise be hidden.
How it Works
What is a PV?
It's kind of a short hand. We have a lot of devices on site, and those devices generate a lot of data. BPMs (beam position monitors), for example, constantly monitor where the beam is relative to the center of the beam pipe. One singular BPM, however, has a lot of signals that it reads out (chief among them x position, y position, and charge), and each one of those signals has a channel dedicated to reading it. It's kinda analogous to TV channels for a BPM TV - x position is on channel 2, y position is on channel 3, etc (except that the channel names are a little more complicated, like BPMS:LI24:801:X). Those channels are PVs.
What does it mean to be tagged to a pulse?
Say that we have a train of pulses with pulse IDs 1 through 4, and say that we have a BPM (beam position monitor) somewhere watching them go by:
That BPM is going to send out data packets for each of its measurement channels every time it sees a pulse. Say that we care specifically about the beam's x position