Cascade Historian™

Version 4.1

Jan 09, 2003

A sophisticated historical data storage and query program for real-time control systems.

With version 4.0, Cogent software now includes source-code compatibility among the QNX 4, QNX 6 and Linux operating systems, a reorganized and expanded API, and other improvements. Version 4.0 of Cogent's tools will not interoperate with version 3 or older. This documentation has been edited and reorganized to reflect those changes. For documentation of Cogent software version 3.x, please contact Cogent Real-Time Systems, Inc.

Go to the Cogent Web Site.

Table of Contents

1. Introduction

1.1. What is the Cascade Historian?

1.2. System Requirements

1.3. Download and Installation

1.3.1. QNX 4
1.3.2. QNX 6
1.3.3. Linux

1.4. Recent Revision History

1.5. Where can I get help?

2. Using the Cascade Historian

2.1. Starting up

2.2. Configuration

2.3. Sending Commands

2.3.1. History Names
2.3.2. Globbing Patterns
2.3.3. Sending commands from Gamma
2.3.4. Using lsend to send commands

2.4. Error Handling

3. System Overview

3.1. System Functions

3.1.1. Data Collection
3.1.2. Disk storage
3.1.3. Services

3.2. Information Flow

3.2.1. Data Flow
3.2.2. Command Flow

3.3. User Interface Models

3.3.1. The Command Interface
3.3.2. Cogent API Functions
3.3.3. The Dynamic Library
3.3.4. Command/Function Correspondence
3.3.5. Binary Data Buffer Functions

I. Commands

add -- adds a single value at a specified time.
apropos -- lists all Cascade Historian commands.
aproposSyntax -- gives a command's syntax description.
bufferIdData, bufferIdDataAscii -- get data from an interpolate query.
bufferIdDestroy -- destroys an interpolation buffer.
bufferIdLength -- gives the length of an interpolation buffer.
bufsize -- sets the history buffer size.
count -- counts the number of histories that match a pattern.
deadband -- sets the history value deadband.
delete -- removes a history from memory only.
describe -- describes a history's current configuration.
disable -- stops data recording.
earliest -- gives the earliest value in a history.
enable -- activates data recording.
exit -- terminates the Cascade Historian.
flag -- converts between history flag values and names.
filebase -- associates the history with a file for data storage.
flush -- writes buffered data to disk.
histdb -- starts the Cascade Historian.
history -- creates a new history.
include -- reads and processes commands in a file.
interpolate -- initiates queries on history data.
interpolatorDescribe -- describes each of the interpolate functions.
interpolatorList -- lists all available interpolate functions.
latest -- gives the latest value in a history.
length -- finds the total number of values in a history.
list -- finds the name of available histories.
register -- registers histories with the Cascade DataHub.
unregister -- unregister histories with the Cascade DataHub.
version -- gets the version number of the Cascade Historian.

II. Dynamic Library Functions

hist_access_buffer -- accesses buffer elements using array-like syntax.
hist_buffer2array -- generates an array from a binary buffer of historian data.
hist_buffer_id_destroy -- destroys an interpolation query buffer.
hist_buffer_id_length -- queries for the number of X-Y pairs.
hist_buffer_id_read -- reads a buffer of data from the Cascade Historian.
hist_bufsize -- sets the history buffer size.
hist_clip_buffer -- clips Y values to fit within a range.
hist_count -- counts the number of histories that match a pattern.
hist_deadband -- sets the history value deadband.
hist_delete -- removes a history from memory only.
hist_describe -- describes a history's current configuration.
hist_disable -- stops data recording.
hist_earliest -- gives the earliest value in a history
hist_enable -- activates data recording.
hist_exchange_buffer -- swaps X and Y values.
hist_filebase -- associates the history with a file for data storage.
hist_flush -- writes buffered data to disk.
hist_gap_buffer -- identifies and fills gaps in data that are too large for interpolation.
hist_history -- creates a new history.
hist_interpolate -- queries history data.
hist_interpolate_data -- interpolates a history and returns data.
hist_latest -- gives the latest value in a history
hist_length -- finds the total number of values in a history.
hist_length_buffer -- returns the number of X-Y pairs.
hist_list -- finds the name of available histories.
hist_register -- registers histories with the Cascade DataHub.
hist_scale_buffer -- performs offset and scaling operations.
hist_stat_buffer -- generates summary statistics on Y-values.
hist_unregister -- unregisters histories with the Cascade DataHub.
hist_version -- gets the version number of the Cascade Historian.

III. Constants

History Flags -- control the behavior of a history.

Index

Colophon

List of Tables
3-1. Cascade Historian Commands and Functions
3-2. Cascade Historian Binary Data Buffer Functions

List of Figures
3-1. Cascade Historian interactions with external and supporting objects.
3-2. Time interpolation
3-3. Interpolation at available values
3-4. Cascade Historian data flow
3-5. Cascade Historian command flow

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