What is a Network?

A network provides a means of connecting multiple devices together for the purposes of exchanging information. A common example of a network is an office where the computers are connected together using an Ethernet network for the purpose of sending emails or printing documents on a networked printer.

Why to Use a Network?

There are many reasons to use a network. Some examples are:

• Data Acquisition from the Control System
• Control devices in a remote location
• Data Sharing Between PLC Controllers
• The ability to program devices from a remote location
• The ability to troubleshoot problems from a remote location
• The ability to integrate all production areas of a plant
• The ability to integrate manufacturing systems with business systems.

Why Are There So Many Networks?

Many different networks exist for a variety of reasons:

• Different manufacturers
• Designed for many devices transferring large data blocks
• Designed to be inexpensive
• Designed for maximum reliability
• Designed to support many communication protocols (languages)

Examples of Networks

Examples of networks used in industrial automation today:

• EtherNet/IP
• ControlNet
• DeviceNet
• DH+
• Remote I/O
• Foundation Fieldbus
• Profibus DP
• Modbus
• AS-i