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Chapter 2: BURT Overview

This chapter provides an overview of the five programs that comprise BURT. The details about the components that appear in this chapter (snapshot files, request files, dependency files, RO and RON process variables and devices) are described in Chapter 3. Again, this chapter merely provides a general overview.

The first two programs, burtrb and burtwb, are used to backup and restore EPICS process variable and device values from and to databases that reside on IOCs, respectively. The next two programs in the BURT suite of programs, burtmath and burtset, are used to modify and combine snapshot files and request files, respectively.

1. burtrb

The backup program, burtrb, takes a set of one or more ASCII files called request files, (request files are fully described in Chapter 3 Section 1). They identify the process variables and devices to backup. burtrb makes a list of all the process variables and devices from the set of request files and takes a snapshot of their values from the IOCs. Their names and values are written to a single snapshot file. Snapshot files are typed (snapshot files and their types are described in Chapter 3 Section 2). The type of snapshot file burtrb always creates an Absolute snapshot file.

2. burtwb

The restore program, burtwb, takes a set of one or more ASCII files called snapshot files, for example like those generated by burtrb, and sets the values of the process variables and devices on the IOCs accordingly.

burtwb restores all the values either conditionally or unconditionally. The user can specifying a set of conditions that burtwb will test before restoring any of the values. The conditions are supplied to burtwb in the form of user-defined dependency files, (described in Chapter 3 Section 3). Dependency files specify conditions about values on the IOCs and the snapshot files. Depending on the specified conditions, the values on the IOCs, and the values in the snapshot files, burtwb restores either all or none of the values to the IOCs. If the user does not specify any dependency files, then burtwb restores the values unconditionally.

In either case, conditional or unconditional restoration, any Read Only Notify (RON, described in section Chapter 3 Section 1.2) values found in any of the snapshot files are reported in a Nowrite snapshot file. If there are no RON values, then no snapshot file is generated.

3. burtmath

The arithmetic program, burtmath, operates on snapshot files. It allows the user to either add or subtract corresponding values found in two snapshot files. As output it produces a Relative snapshot file containing the sum or difference of the two input snapshot files.

burtmath also allows the user to multiply the contents of a single snapshot file by a scalar constant. The output is a snapshot file that inherits its type from the input snapshot file.

4. burtset

The set operation program, burtset, operates on request files. It allows the user to perform mathematic set operations, (union, intersection, or difference), on two request files to produce a new request file.

5. burtconvertsnap

The final BURT program, burtconvertsnap, is a conversion program. It operates on a single snapshot file by converting its format to either SDDS or non-SDDS.

6. Execution

BURT can either be executed directly from a UNIX prompt or from a Graphic User Interface (GUI) that we have provided. The instructions regarding how to execute BURT in either mode (UNIX or GUI) as well as a detailed description of BURT's components are in the following chapter.

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