Adapting XAL for LCLS

1. Adapting XAL for LCLS In order to use XAL as a framework for high level applications development for LCLS, there are two main tasks that must be completed. • Setting up the RDB to support XAL applications • Representing the LCLS accelerator components for XAL applications and the on-line model

2. Representing Accelerator Components • There is a significant amount of time required to set up the RDB for XAL and a new system. During this time developers may work with XAL applications and on-line model by creating an accelerator configuration file by hand. • We had some initial confusion in configuration/model assumptions(relative vs. absolute positions, how magnets are split, definition of sequence, scenario, etc) which made it difficult to create this configuration file at first. • The component interface classes (SMF) are quite specific to the device (as to be expected). New component types need to be added, and some accelerator components need to be re-defined for LCLS • For example, SNS BPMs measure different parameters than LCLS BPMs, hence the BPM interface class must be sub-classed or newly defined • New machine element classes must be defined for a complete LCLS model (solenoid, RF structures for LCLS). The process for creating these classes seems straightforward; documenting this process would be helpful. • Mid-level documentation, some class and sequence diagrams, would be very helpful to the XAL novice • However, excellent support from the SNS XAL team has helped overcome all difficulties so far - thank you!