In System Integration, Software Rules

DN Staff

April 14, 2011

9 Min Read
In System Integration, Software Rules

For years, the industrial automation industry hascapitalized on advances in microprocessors and computer platforms to deliverever-improving control solutions. Now the big trend is focused on the front endof these advanced computing systems, with the development of automation systemsoftware that enables system designers to more fully utilize the powerfulhardware at their disposal and make control systems more intuitive.

The Ease of Use Challenge
"Software is the key to control system development, andthe importance of ease of use comes down to the software inside the controlsystem," says Tom Jensen, technology manager at B&R Industrial Automation. "Machinebuilders are looking for PC-based controls, but with the technology we have inour cell phones and laptops."

PCs as part of the machine can provide access to Web-basedtroubleshooting tools that everyone knows as well as better graphic interfacesfor users. With this type of connectivity, if a machine has a problem, insteadof an amber light glowing on top of the machine, the HMI is playing videos tohelp the operator fix the machine.

"In a sense, it is nothing new because PCs have been around foryears but the expectation since 3G smart phones have come out is that 'I havean iPhone and I've never been trained on it, but I can do everything I need todo.' That kind of intuitive operation is now being required of machinebuilders," Jensen says.

A lot of people will look at software in a modern machine, andsay it is complex. But in reality, software is only reflecting the complexityof the machines now being made. If we go back 10 years, for example, asophisticated machine may have had two servos on it, and it allowed a certainpart of the machine to changeover automatically, but now it might have 20servos.

"Old ideas that have not previously been practical in programmingare now starting to come forward again," says Jensen. "S88 is an old conceptthat has been around forever in batch manufacturing. It is based on the conceptthat if I have a machine with 20 servos, I should be able to find 20 servoobjects in the software. As a maintenance person, I should be able to go up toany of those software objects, manipulate it and get a proper reaction out ofthe machine. It's simple, but few companies are simplifying their software tothat level."

Jensen says an S88 approach to controlling a servo is to have afunction block for every servo. If that approach is in place, and the servocomes up with an alarm, the software may say the motor is overheating. "Thesoftware object is the window into that motor," he says.

Software Development Tools
"When it comes to simplifying system integration formachine builders, one significant improvement request we hear about is the needfor improved software development environments," says Paul Ruland, productmarketing, automation systems for SiemensIndustry Inc. "One key to this is the programming and configurationsoftware used for automation devices, and convergence around integrateddevelopment environments that offer one development software for all automationdevices and tasks."

A variety of automationsuppliers are pursuing this goal, and the latest Siemens releases ofdevelopment software include the ability to do controller logic for a PLC, PAC,embedded controllers and IPC for soft control. It also extends to visualizationfor all types of HMIs as well, up to PC-based SCADA systems and all of thenetworking required between these devices.

Motion control (servo, stepper, variable frequency drives and thehardware infrastructure around them) as well as specialty functions likemachine safety, remote I/O and Web connectivity, is all addressed using onedevelopment environment and one user project.

"This is a significant step compared to traditional methods thatincluded a development package for the PLC, a development package for HMIpanels and SCADA, plus a variety of add-ons," says Ruland. "The add-ons mightprovide utilities for network configuration which requires saving a separateconfiguration file for a particular project, or to configure safety-rateddevices or PID for tuning loops."

The current trend now is to have all of these functions cometogether in a single development environment or framework - an approachembodied in products like Siemens' Totally Integrated Automation (TIA) Portalsoftware. This software is designed for use with all of the company'scontrollers, HMI panels, industrial network infrastructure and SCADA systems.

"Our existing hardware architecture had a lot of built-incompatibility for networks and interfaces, but now we are bringing all of that tothe software configuration tools, says Ruland. "Before, each function had to beconfigured separately and combined together."

Now, within the TIA portal, the software has the intelligence toself-describe the system components, detect systems on the network and pullthem together. Using a common, tag-shared database, the user can update achange between all or some of the devices rather than importing and exportingtags or data types between all of the devices in the system. The new softwarealerts the user that they have made a change, and how to propagate that change.

"The key for OEMs and systemintegrators implementing automation systems is a shared compatibility insidethe software which eliminates the need for the user to duplicate that effort,"says Ruland. "This includes maintaining individual software packages and savingall of the configuration files. For a system engineer, their project isdeveloping a machine and not the individual software program, the separateconfiguration of the network or one PID tuning algorithm."

Doing More with Less
Bosch Rexrothhas responded to this simplification of system integration trend with thedevelopment of its EasyHandlingtechnology. Here, standard function blocks can address the majority ofindividual application needs, along with a new commissioning tool that narrowsthe scope of system configuration tasks and helps reduce the time required todevelop custom software solutions.

"During the last few years, more and more system integrators havedownsized and have fewer engineering resources. This trend means that they arelooking to automation suppliers to deliver products that are easier to use,"says Richard Vaughn, a robotics product engineer for Bosch Rexroth, linearmotion and assembly technologies.

If you look at the mechanicalsolutions such as linear modules used with Cartesian robots and integratedcustom solutions, system integrators traditionally did the majority of theintegration work. Now, integrators are looking for assembled solutions and areincreasingly purchasing linear modules complete with brackets that are pre-madeand easy to configure, as well as dropping in subassemblies rather thanbuilding the system themselves.

The concept behind the EasyHandling software is to have all driveand control technologies integrated with linear systems, standardizedmechanical and electrical interfaces, and new commissioning assistants tosimplify the integration process. The EasyHandling system is based on athree-level architecture, which includes basic, comfort, and advanced variantswhich cover all levels of automation from mechatronic actuators and intelligentaxes to the preconfigured system solution. The "basic" level of the systemencompasses mechanical single- and multiple-axis systems that are ready toinstall, with motors and pneumatic actuators such as grippers and rotarymodules, as well as sensors.

Preconfigured Rexroth servo drives expand the entire range ofbasic axes at EasyHandling "comfort" level. New hardware supports severalEthernet protocols including communication with IndraDrive Cs controllers usingSERCOS III Ethernet, Profinet IO, EtherNet/IP and EtherCAT.

EasyHandling "advanced" integrates a scalable, preconfiguredmotion-logic controller compliant with the IEC 61131-3 and PLCopen standardsthat offers predefined functions for handling applications. The controller ispre-programmed to support coordinated point-to-point motions, along withsmoothing and optimized handling paths for Cartesian systems. The drivecontroller software provides operator maintenance instructions that correspondto the specific run times and travel paths based on the axis-specific mechanicaldata defined.

Model-Based Design
"A significant trendgaining a foothold in automation system integration is model-based design,"says Sal Spada, a research director specializing in industrial automation forARC Advisory Group. "Companies outside of the automation industry aredeveloping software development platforms that enable engineers to take anabstract view of their problem using design tools that are already applied intheir work environments. The environment combines both the underlying systembehaviors (aka models) and control strategy.

"The tools used by controlsystem engineers are now allowing them to port their applications onto generalpurpose automation systems," says Spada. "This is significant because thegeneral automation platform is now becoming a general-purpose computingplatform."

Furthermore, the ability to do modeling and simulation will lowerthe cost of deployment over time and eliminate some of the hardware prototypingassociated with machine building.

The MathWorks is seeing a significant increase in the use ofmodel-based design, which has been used in the automotive and aerospaceindustries for nearly two decades, among machines.

"With model-based design, themachine builder's goal is to design better equipment by capturing importantdynamics resulting from the interaction of the mechanical, electrical andcontrol systems. In other words, mechatronic system design," says Tony Lennon,industry marketing manager for The MathWorks. "The engineers at the OEMs aremotivated to find integration errors and poor performance early in thedevelopment process, well in advance of the hardware prototype stage when thecause of design problems is costly to isolate and correct."

Another benefit for machine builders is the ability to be moreinnovative through testing of new designapproaches and control strategies in the lower-cost simulation environment.Using model-based design means engineers can devote more time to creatingbetter products, rather than spending that time troubleshooting hardwareprototypes that fail on the test floor.

To support this greater adoption of model-based design by machinebuilders, The MathWorks, which hastraditionally supported C code (for DSPs and microcontrollers) and HDL (for FPGAsand ASICs) generation, has also released Simulink PLC Coder that adds IEC 61131structured text generation capabilities for PLC systems.

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