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High performances networks for motion control and robotics.

Fast networks

  Automation > Resources > Technologies > Networks > Fast control data buses  

  Fieldbuses in factory automation

Instrumentation networking  


CAN bus, ControlNet, Drivecom, Ethercat, MACRO, Mechatrolink, Powerlink, Profidrive, SERCOS, SynqNet.

Real Time And Deterministic Networks With High Performances

The control buses are specialized fast industrial networks with real time and deterministic features.

They are especially designed for fast control and automated applications requiring very short response delays.

Typically, these applications concern motion control, multi-axes control, servo-drives control, robotics, fast counting, special machines requiring short response time in writing and reading the inputs and the outputs, or interactive devices requiring quick data exchanges in order to get an efficient synchronisation (between a programmable controller and a robot controller for instance).

Some of these control networks have been designed to be embedded in the system to be controlled.

The control networks providing the highest performances can benefit of technologies like Fast-Ethernet, Gigabit Ethernet and Real Time Ethernet (RTE) by using the ISO 1588 standard or any other synchronisation technology.

Some of these control buses implement the real time capabilities in the interfaces in a software manner, some other in a hardware manner (using ASIC or FPGA components for instance).

CAN BUS - Controller Area Network Bus

CAN Open specifications, Technical papers, DeviceNet.

Can Bus, A Network Embedded In The Vehicles

Controller Area Network (CAN) is the network developed for embedded use in cars, and more generally for almost any embedded control.

CAN bus is also often used for servo-drives networking in motion control applications too, although it does not provide any deterministic features natively.

CAN Bus Specifications And Protocol Description  

CAN OPEN Association -

CAN BUS Technical Papers  
DeviceNet Technology Overview  

DeviceNet is a control bus initiated by the Allen Bradley company, and is a part of the CIP network family.

It is based on the Can Open standard specifications for the data link layer, and uses the CIP protocol for the upper layers.

CONTROLNET - Fast Network For Inputs And Outputs Access


A Control Network With High Performances

"ControlNet" is a real time and deterministic control bus, part of the CIP network family based on the CIP protocol and on a producer-consumer architecture.

It can be installed by using several topologies (linear, star, tree) and it offers redundancy and safety options.

Originally, CONTROLNET uses a time sliced algorithm (Concurrent Time Domain Multiple Access - CTDMA) to get real-time and deterministic capabilities in order to transmit time critical data.

The CONTROLNET Technology and

DRIVECOM - Talking With Axis Controllers

Drivecom specifications.

A Communication Interface To Interact With Inverters

DRIVECOM is a standardized communication interface designed for accessing drives. Its actual version is called "DriveServer".

The DriveServer specifications are based on the OPC interface standard.

Actually, DriveServer acts as an OPC layer, interfacing an application layer acting as an OPC client and a communication layer acting as an OPC server.

Thus, DriveServer benefits of the advantages offered by the widespread OPC standard technologies and run in a very flexible way.

And consequently, it is hardware independent and quite universal since it works with any OPC client and any OPC server applications (It is implemented into Profibus devices and is compatible with Profidrive and Profibus DP for instance, by interfacing the Profibus OPC servers).

To work fine with any drive controller, DriveServer uses a drive description called "Drivecom Device Description" which is based on the XML (eXtended Markup Language) standards.

This device description structures the informations related to the functionalities and to the parameters of the drive to control.

Drivecom Specifications  

The DRIVECOM User Group promotes the DriveServer technologies and provides all the specifications in the download section, with technical guides related to the Interbus and to the Profibus interfaces, and the specifications of the Drivecom Device Description.

ETHERCAT - An Ethernet Fieldbus

Technical overview, Detailed description of the technology.

A Fast Industrial Ethernet Network To Control The Machines

The EtherCAT technology is based on the Ethernet standards, which have been adapted to deliver a fast and deterministic control networking technology at low cost with real time capabilities.

In order to implement real time and deterministic characteristics over Ethernet, the designers have chosen software protocol solutions rather than hardware solutions, thus no specific hardware is needed, users and peripherals (controllers, computers, routers, switches) can access the network with standard Ethernet interfaces, and consequently with standard connections.

The Ethercat cycle time is below than 100 µs.

Ethercat Technology And Technical Papers

Ethercat User's Manual  

This document explains all you want to know about Ethercat (in its version 1.01).

MACRO - Motion And Control Ring Optical

MACRO technology overview.

A Communication Interface For The Multi-Axis Controllers

MACRO is a digital interface developed by Delta Tau Data Systems designed to connect multi-axes motion controllers, amplifiers, and I/O.

MACRO is an Ethernet based protocol that uses a multi-mode fiber optic (FDDI - Fibre Distributed Data Interface) or twisted pair copper (CAT5) which is called 100 BASEx, implemented by using a ring topology.

MACRO Technology  


Mechatrolink technologies basics.

A Motion Control Dedicated Field Network

MECHATROLINK is a field network positioned as a motion control bus.

Only one communication line is required to connect 30 stations on a network. This can reduce costs for wiring.

Since the Mechatrolink system is all digital and communicate directly with the devices, there is no need to connect any analogical signal, consequently speed or torque references are transmitted directly without using a digital-analogical converter (DAQ).

Mechatrolink Technology Overview


Introduction to Powerlink and Open Powerlink.

A Fast Ethernet Real Time Network For Motion Control

"Ethernet Powerlink" is a fast, real time and deterministic Ethernet control bus, based both on the Ethernet standard and the CanOpen standard, leading in a CanOpen real time and deterministic network.

ETHERNET Powerlink focuses on the transport layer and the cycle time is typically 100 µs while the network jitter is below 1 microsecond.

The Ethernet Powerlink Technology In Details  

This folder presents the "Ethernet Powerlink" technology and its main characteristics.

OpenPowerlink As An Industrial Ethernet "Open Source" Solution  

"OpenPowerlink" is an open source solution "Open Source" which provides a library with all the required functions and services to implement master stations and slaves stations according to the POWERLINK protocol.

The library is implemented in C language and respects all the specifications of the ANSI standard - The American National Standard Institute.

Powerlink runs with Ethernet standard control cards, with time cycle down to 400 microseconds ensuring a very good synchronization.

Using co-processors, "openPOWERLINK" can even ensure time cycles down to 0.1 millisecond (100 microseconds).

You can download the source code and the full documentation from the openPowerlink site.

An Open Powerlink configuration open source software is available too.

The POWERLINK network is well known for its communication capabilities for axis control and fast control. Nevertheless, it can be used as a simple fieldbus transporting data or accessing a whole of sensors.

PROFIDRIVE - Profibus Based Protocol For Drives

Profibus Alliance.

Profibus Alliance

SERCOS - Serial Real Time Communication System

Standard overview, Technical introduction

A Communication Interface For Inverters And Axis-Controllers

SERCOS (SErial Real-time COmmunication System) is a real time and deterministic protocol.

In its first versions (Sercos I and Sercos II), it has been especially designed to interface drives. Nowadays (Sercos III) it is more universal and Sercos is developed to be used as a motion control bus.

The SERCOS III version is an Ethernet and Ethernet IP standards based network embedding the SERCOS interface, the whole implemented in a linear topology whether redundancy is not needed, or in a ring topology to benefit of redundancy features.

The sercos III interface groups more than 500 standardized parameters, quite universal to be used by all control devices.

SERCOS transmissions use a time sliced process, running cyclically in a master-slave architectures in order to transmit telegrams.

Actually, one of the technologies used by SERCOS to manage real time communications is the basic token communication technique.

To manage efficiently the data, SERCOS uses two channels through Ethernet.

For safety applications, SERCOS embeds the CIP safety standard protocol.

SERCOS Standard Description  

In the "download" section, you can get technical papers related to all the versions of Sercos, and the Sercos standard specifications.

SERCOS Standard Description


A Fast Control Bus Especially Designed For Motion Control

Synqnet was a 100 base T industrial Fast Ethernet control interface particularly intended to OEM products.

Its main characteristics were its high speed, its diagnostic and hot plugging capabilities, and its low cost.

The open data layer has been implemented by Motion Engineering Inc, and 350 000 Synqnet nodes habe been sold.

Apparently, Synqnet has been discontinued since 2008, but the Synqnet organization still delivers a short introduction to the Synqnet technology ( ).

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