Chapter 5. The DataHubPoint Class

Table of Contents

5.1. Overview
5.2. Categorized List of Methods

The DataHubPoint class represents a DataHub point object.

5.1. Overview

Syntax

For C++:

class CDataHubPoint

For Java:

public class DataHubPoint

For C#:

public class DataHubPoint

Remarks

DataHub point objects are the fundamental objects used to write, receive and manipulate data in the DataHub, via the DataHubConnector class. The DataHubPoint class provides a rich set of facilities to create, modify and inspect these objects.

DataHub points possess the following properties:

value

A value whose type is one of PT_TYPE_STRING, PT_TYPE_REAL (a double) or PT_TYPE_INT32 (an int). The value is stored in a corresponding format, and can be converted by the various utilities to access the value.

quality

Indicates whether the DataHub has been updated with actual data or if a point is uninitialized. This is typically either PT_QUALITY_GOOD or PT_QUALITY_BAD. Connection status can also affect the point quality.

confidence

A user defined value, typically in the range of 0-100%. This can be used to model 'aging' of a point, and support 'fuzzy math' algorithms.

timestamp

Tags the real-time origin of the point as it is distributed. Typically this is set by the software module originating the value of a point. It is modelled as seconds and nanoseconds, providing a resolution that is limited only by the OS.

userdata

Allows the user to associate with a specific point whatever object may be useful to the application. This is primarily used by the point cache cability provided by the DataHubConnector class (see initializePointCache).

locked

Controls access to the point.

security

Controls access to the point.

flags

For internal use.

Requirement Statements

For C++:

#include <CDataHubPoint.h>

For Java:

import cogent.DataHubPoint;

For C#:

using Cogent.DataHubAPI;

See also

Categorized List of Methods, DataHubConnector