Cogent C API and Utilities : Version 6.4
	Chapter 1. Introduction

Chapter 1. Introduction

Table of Contents

The Cogent C API is an easy-to-use set of functions that fall into five main categories:

Point structure, storage, and manipulation.

Inter-process communication (synchronous and asynchronous).

Global name server registration and lookup.

Cascade DataHub reading, writing and exception reporting.

Device driver control.

The Cogent Utilities are used by several Cogent products, primarily to facilitate inter-process communication.

To use the Cogent C API, you should be familiar with C programming.

1.1. When to use the different Cogent APIs

There are four Cogent APIs, grouped as:

DataHub APIs for C++, Java, and .NET

Cogent C API

The Cogent C API

This API lets you write high-speed clients that can interact with the Cascade DataHub, Cascade Historian, Cascade TextLogger, CIF Driver, DVN Driver, PFB Driver, and Gamma. It works in Linux, QNX 6, and QNX 4. Interprocess communication relies on Send/Receive/Reply message passing. In Linux, this is supported by Cogent's SRR Module. In QNX, this is supported by QNX's own Send/Receive/Reply protocol.

The DataHub APIs for C++, Java, and .NET

These three APIs share, as much as possible, common methods and syntax. For this reason they are distributed in one package and documented in a single book.

The DataHub API for C++ lets you write programs in C++ that connect to the DataHub over TCP, namely LAN, WAN, or the Internet.

The DataHub API for Java lets you write programs in Java that connect to the DataHub over TCP, namely LAN, WAN, or the Internet. In addition, it lets you create web browser applications that receive and display live data from the DataHub.

The DataHub API for .NET lets you write programs in .NET that connect to the DataHub over TCP, namely LAN, WAN, or the Internet. This API is implemented in C#, but can be used with any .NET language.

The following table shows the availability and support for these APIs in Windows, Linux, and QNX:

Language	Windows	Linux	QNX 6	QNX 4
C++	supported	supported	supported	unsupported
Java	supported	unsupported	unsupported	not available
.NET	supported	may be available using Mono	not available	not available

The C++ API that runs in Linux and QNX is included in the Cogent C API archive.

For more information on these APIs, please refer to the DataHub APIs for C++, Java, and .NET manual.


Part I. Programmers Manual		1.2. Function Naming Conventions