UKRI-2171 Vista to EPICS project

Initial tasks

Move OpenVMS applications to Linux/EPICS. Related to WP-7

The Open VMS servers that host the V-system run many different control applications written in VSI Basic and C. These applications shall be converted into Python and moved to the new Linux servers hosting EPICS.

The first step would be to document each of these software applications. The document shall include a high-level functional description of each application.

Some of these applications are or will be obsolete. The in-house team will use the delivered functional descriptions to identify which of these applications are obsolete and therefore do not need to be moved into the new Linux servers or EPICS.

After this step is done the contractor team will proceed to translate and move the remaining applications from the OpenVMS/Vsystem servers to the Linux/EPICS architecture.

Many of these applications are called from a control screen. A validation process needs to be done to make sure that all the elements in the control chain (screen, application, middleware) are properly linked and operate as expected.

Vsystem specific code includes:

• Readers – input data from controlled hardware, e.g. FINS, Modbus, CPS (internally-developed XML format), etc. Approximately 10 readers, all written in ANSI C.
• Handlers – output data from controlled hardware (same as above). Approximately 10 handlers, all written in ANSI C.
• Applications – either triggered by user action or scheduled. There are a minimum of 346 applications (~125k Lines of Code (LOC)) written in VSI Basic applications, and a further 28 written in C ~2.6k LOC).
• Scripts – a mixture of simple wrappers around other applications, system functionality, and more advanced scripting. There are a minimum of 493 scripts written in DCL (Digital Command Language; the default command line interpreter for OpenVMS systems) (~20k LOC) and a further 26 written in Python (~2k LOC).
• Converters – strictly change engineering units to display units or vice versa, but often used for more complicated purposes internal to Vsystem triggered uses. 25 files (~4.5k LOC) written in Ansi C.
• Vsystem shareable images – overlap with applications above, primarily VSI Basic. These are user generated libraries called by Vsystem, and unlike applications are not runnable separately in a shell.

Validation platform. Related to WP-2, WP-6 and WP-7

Design and build a platform to test and validate the V-system screens that are converted into EPICS, the software applications that are moved from the OpenVMS server into the Linux server and the new middleware interfaces.

This platform will have to check that the EPICS screens are properly linked with the applications in the Linux server and the middleware that conform the rest of the control system. A list of the different types of middleware that we use at ISIS will be given in the TO.

It will also be used to test and validate any new or modified screens, applications and interfaces before these are implemented in the control system.

Apart from the platform itself, a method for the testing and validation of these components as well as a template document for documenting these tests should be given.