Bruno HÉNON - Automation & Control Engineer Freelance Services in factory automation, designing, programming, installing and subcontracting worldwide

Exchanging data with the sensors and the actuators.

Sensors networks

See also …

 

  Automation > Resources > Technologies > Networks > Sensors and actuators  

  Image transfer networks

IO-link, a field communication interface  

SENSORS AND ACTUATORS NETWORKS

AS-I, DeviceNet, Interbus, P-NET, Profibus-DP and Profinet-IO.

Talking With Sensors And Actuators Over A Network

The sensors and actuators networks are low level networks well adapted to the automation of workshops, of production lines or of machines. The main purposes of these networks are to reduce the cost of the connections, to make easier the installation, the adjustments, the operations and the maintenance of the industrial automation devices linked to the network. Some network interfaces specify the network infrastructure, the hardware protocols and the software protocols all together while some other interfaces - such as IO-Link - specify only the exchanges of data. Many of these systems encapsulate their own protocol into other ones too, allowing them to adopt various topologies and media.

AS-I - AS Interface

Technical basic knowledge.

A Low Cost Network Easy To Install

The « AS-I bus » is a low cost sensors and actuators network based on a master / slave architecture and supports the most current topologies.


The data are transmitted through hardware methods, firstly by encoding them ( Manchester encoding ), secondly by modulating the power line with alternate pulse for data transfer ( ATM technology ). The time critical data ( the inputs and the outputs of the slaves ) are transmitted by cyclic polling, when the other types of data ( such as configuration parameters ) are transmitted asynchronously.

This communication system can provide safety features when necessary.

Curses, Tutorials And Technology Introduction

The « AS-Interface » association provides a whole of technical information by e-learning in its virtual academy.

www.as-interface.net

DeviceNet

An all in one CAN and CIP I/O bus system, Technical overview, Installation guide.

An Automation Network For Inputs And Outputs

« DeviceNet » is an industrial communication system part of the CIP network system family. It has been designed to operate communications at the lowest level of an automated plant, in order to exchange data between programmable controllers and field devices.

The system is technically based on CAN bus concerning the physical layers and on the CIP protocol concerning the upper layers. Actually, its protocol is an adaptation of the CIP protocol to the CAN standard, which its designer have added some useful additional features to, such as hot plugging, diagnostic capabilities, redundancy capabilities and more.

This communication process uses both the producer-consumer model and the client-server model in order to manage the data flow between the different installed devices. It exchanges the data from point to point, choosing either a master-slave architecture or a distributed architecture, according to the desired configuration.

DeviceNet Educational Papers
DeviceNet Installation Guide

This guide focuses on the media and how to design and to install such a communication system. You will learn here how to set up a network, what are the available topologies and what are the different available media. Then, you will read a description about the cable system and its components, the connections, how to compute the power requirements, how to diagnose network problems and how to prevent them.

www.odva.org

Interbus

What is Interbus ? , Interbus technology basics, Technical papers.

A Fast Industrial Network For Sensors And Actuators

« Interbus » is a sensors and actuators deterministic bus originally designed by the Phoenix contact company. Nowadays, the whole of this technology is embedded into the Profinet IO network system provided by the Siemens company ( Profinet IO is compliant with the previous versions of « Interbus », by using a dedicated proxy as a gateway ). « Interbus-Safety » is a specific version of « Interbus », which is dedicated to safety networking applications.

Main specificities.


Since its hardware specifications suggest using a single-line-only through all the devices with the objective to send the requests and the answers together, the network topology has evolved towards a ring topology with branches looking like a tree topology.

According to the communication process, the protocol is based on a single-master / slaves model, and exchanges the data through two channels : one for the process data ( the inputs and the outputs ) and the other for the services data ( configuration, diagnostic and more ). In its late versions, « Interbus » integrates the TCP/IP protocol in a separated channel.


To operate the configuration, the monitoring and the diagnostic of Interbus, it is enough to use the CMD software which is a single tool available for all the control systems.

Technology And Network Interfaces

The « Interbus » association provides some documentation about its networking technologies that you can download freely.

www.interbus.de

Technology Overview

IO-link - Communication Interface For Sensors And Actuators

Technology Overview And Basics

This system is a communication interface intended for the lowest field devices such as sensors, actuators or instruments.

Here you will discover that strictly speaking, this communication system does not consist in a network, but it rather consists in a data exchange interface extension for field bus systems, increasing their potential.

This data transmission technique has the objective to make a device stock uniform, proposing supplementary appropriate and useful functions in the same time ( diagnostic, adjustment ) for installation, maintenance and operation.

The bus specifications have evolved with the Ethernet TCP/IP integration. By the time now, the transmission process encapsulates the original messages ( RS485 ) into the Ethernet frames, resulting in a well adapted distributed network serving automated industrial plants.


www.bh-automation.com

P-NET - The Process Network

Purpose & concepts , Technology basics, Installation guide.

An I/O Network For Process And Manufacture Industries

« P-Net » is a process fieldbus, registered as an international standard under IEC 61158 reference. This process dedicated communication bus has been designed by the « Proces Data » company in Denmark which continue to maintain it.


This industrial digital communication system has been expressively designed to exchange data with sensors, actuators and measurement devices and to provide device configuration as well as device diagnostic services.

The multi-master / slaves model is used to process the communication, using the token communication technique to manage the master accesses ( implemented as a virtual token ).

This network supports multiple topologies ( ring, tree, star ), with some other capabilities like segmentation ( multi networks technique ), hot plugging, redundancy, while being rather media independent. One of its specificities consists in the possibility to modify the address of any device while the bus is operating.


By the time being, P-Net supports Ethernet TCP/IP, since it embeds the early RS 485 messages in the Ethernet frames, leading in a full factory automation distributed network system.

Technology Overview

The International « P-NET User Organization » ( IPUO ) promotes this standard and provides some technical informations.

www.p-net.dk / www.proces-data.com

P-NET Installation Guide

Here, the « Proces Data » company - the designer of the « P-Net » digital communication system - presents the technology developed by its team and how to use it as its best.

www.proces-data.com

Profibus-DP

Tutorial And technical Informations

Profinet-IO

Technical Documentation

The « Profinet-IO » network ( a Profinet bus specialized as a network talking with sensors and actuators ) seems not to be a topical question yet.

The solution used by the Siemens company to answer this need is the Interbus network, following a strategic deal with the Phoenix Contact company by merging their solutions. Nevertheless, to satisfy your curiosity, or whether you need it, you will take advantages by reading the introduction to Profinet IO provided by www.rtaautomation.com.

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