1 INTRODUCTION

1.1 PURPOSE

This document is the User Manual for the HOS/Broker for Observation Blocks version 1.145 and is intended to provide all the necessary information for the installation and use of this module from an end-user's point of view.

1.2 SCOPE

This document describes how to configure and use BOB as a high level tool for executing observation blocks, showing primarily the VLT Control Software side. It does not consider in any detail the creation, modification or scheduling of observation blocks, nor the lower level modules (DCS, ICS, TCS) which are actually acquiring the astronomical data belonging to the observation blocks. Neither does it deal with the subsequent archiving or pipeline-reduction of these data.

1.3 APPLICABLE DOCUMENTS

[1] VLT-ICD-ESO-17240-19200, 2 31/07/2002 -- ICD between VCS and OH

1.4 REFERENCE DOCUMENTS

The following documents are referenced in this document.

[2] VLT-MAN-ESO-17220-0737, 3 28/03/2002 --- VLT SW HOS/Sequencer User Manual

[3] VLT-MAN-ESO-17220-1349, 1.1 28/08/1997 --- VLT SW HOS/BOB SW Maintenance Manual

[4] VLT-SPE-ESO-17240-0385, 4 13/01/2005 --- VLT SW INS Common Software Specification

[5] VLT-MAN-ESO-17220-3676, 1 26/10/2005 --- VLT SW HOS/Audio SW User Manual

1.5 ABBREVIATIONS AND ACRONYMS

The following abbreviations and acronyms are used in this document:

CCS Central Control Software

GUI Graphical User Interface

HOS High Level Operating Software

HW Hardware

ICS Instrument Control Software

OBD Observation Block Description

OH Observation Handling

OS Observation Software

OT Observing Tool

P2PP Phase II Proposal Preparation System

SW Software

TBD To Be Defined

VCS VLT Control Software

VLT Very Large Telescope

WS Workstation

1.6 GLOSSARY

Observation Block
A high level view of VLT operations. An observation block is the smallest schedulable observational unit for the VLT. It is a rather complex entity, containing all information necessary to execute sequentially and without interruption a set of correlated exposures, involving a single target (i.e. a single telescope preset). It contains a.o. one or more template calls, i.e. it describes what templates to call with which parameters. Consequently, during Phase II Proposal Preparation, observers will have to build observation blocks, using the tools provided for that purpose, by selecting templates, defining parameters, and giving additional parameters for scheduling and data reduction.
The contents of an Observation block is reflected in ASCII format by a so-called Observation Block Description.

Phase II Proposal Preparation
The P2PP system assists the user in preparing Observation Blocks.

sequence, Sequencer script
a set of commands in Sequencer language, generally intended to define and execute a series of related observations. These sequences are to be interpreted by a sequencer shell.

Tcl/Tk
Tool command language / Toolkit. A general purpose scripting language designed and implemented by Dr. John Ousterhout of the University of Berkeley, CA (presently working at Sun Microsystems Laboratories).

Template
An entity containing a sequence (Sequencer script), dealing with the setup and execution of one or more exposures. It is literally a "template", to which a set of parameters belong whose specific values determine the exact behaviour of its execution.
Technically, a template is an object belonging to the Template class, and has several components, one of the being the Sequencer script defined above. Other components are the template signature file and the template parameter GUI.
Templates should generally have the complexity of setting up and executing one or a few exposures.

Template call
The name of the template to execute, with its parameter values.

Template signature file
This is a description of a template and its parameters. It contains a.o. information about the type and allowed ranges of the parameters, so that a trivial validity check can already be performed when parameters are entered via the template parameter GUI.

1.7 STYLISTIC CONVENTIONS

The following styles are used:

bold
in the text, for commands, filenames, pre/suffixes as they have to be typed.

italic
in the text, for parts that have to be substituted with the real content before typing.

teletype
for examples.

<name>
in the examples, for parts that have to be substituted with the real content before typing.

bold and italic are also used to highlight words.

$ indicates a UNIX shell prompt