An alternative to DCS or PLC/SCADA?

Traditionally, users have had a choice between a DCS or a PLC/SCADA approach when selecting a control system for use in process control applications. Richard Sturt, Rockwell Automation business development manager, process Industries, believes that Rockwell can offer a solution for users needing elements of both of these approaches.

A key benefit of traditional DCSs was that the suppliers took a ‘systems approach’ and it was designed for large scale applications. Much of the work of integrating different parts of the system was taken care of by the DCS vendor by using a single database for the complete system.

The DCS approach is to configure the system using standard control objects and faceplates, reducing engineering and providing standardisation. Most DCSs also offer fieldbus communications, tools for process optimisation and asset management packages to improve maintenance. More recently DCS suppliers have introduced more scalable solutions for smaller applications

However, there are a number of potential shortcomings in the DCS approach. Many process plants have a large number of OEM packages that need to be integrated with the overall process control system and it is unlikely that the OEM will use a DCS for their control system. In some manufacturing processes there is a requirement for different types of control; process, discrete, high speed, drive control, motion control or machinery safety. The DCS is not designed to cope with these types of applications and, if a manufacturing process covers multiple disciplines, the DCS will only ever be suitable for part of the system.

DCS has, traditionally also been an expensive product to support throughout its life. Annual licensing and support costs can become a significant part of the overall cost of ownership. The majority of DCSs are engineered and supported by the original manufacturer and are not freely available though other channels, leaving the end user reliant on its DCS vendor.

Most DCSs had closed and proprietary system architectures. More recently suppliers have adopted more open standards but, in many cases, this approach has limitations which often makes it complicated to integrate with MES and other business systems.

The PLC/SCADA approach
Although PLCs were originally developed for discrete applications, most cover a wide range of applications. The term Programmable Automation Controller (PAC) is now used to describe many products to distinguish them from older systems that were focused on discrete logic. This flexible approach offers multiple programming languages, open communications, and scalability for different applications. There are many systems integrators able to integrate PLC/PAC technology, often with specific industry or application knowledge. This approach is also ideal for OEMs who can select a cost effective product to meet their requirements.

Although PLCs and PACs have become more powerful they still have a number of features that are missing when compared to the DCS approach.

A typical PLC/SCADA system has at least two databases. The user has to configure the PLC database and then separately configure the database in the SCADA system. At initial engineering stages there may be an option to import the PLC database into the SCADA system but this will require manual modification as changes are made during commissioning and when enhancements are made. If additional software packages are required they are likely to have their own separate databases too, that will need to be configured.

Another potential weakness is that not all PLCs have features required for demanding continuous process control applications. In some cases they will lack the ability to modify the system on-line or will not include high availability features like redundancy from I/O modules to supervisory systems.

Process optimisation and asset management is another area where traditional PLCs may be lacking compared to a distributed control system.

The best of both worlds
A true ‘Plant-wide Automation’ approach takes the best features from DCS and PLC/SCADA systems and combines them into a single system. It combines the ‘systems approach’ of a DCS and flexibility of a PLC/PAC to provide a solution for multiple applications.

This approach has benefits that can improve plant performance and reduce costs. A single architecture can be selected for any application whether it is continuous process control, high-speed OEM equipment or a small batch reactor. It simplifies integration and reduces engineering costs. The resulting system will have a seamless communications architecture allowing access to plant data for process optimisation, asset management and integration with MES. Support costs will also be minimised by reducing training requirements and the cost of holding spares.

Rockwell Automation has recognised the benefits of combining the features of Distributed Control Systems and PLC/SCADA solutions into a single Plantwide Automation system with its PlantPAx. As part of the companies Integrated Architecture, it allows a single architecture to be used for a wide range of applications, including process, batch, drives, motion and safety.

The importance of being able to address such a wide range of applications is key to a truly plant-wide automation system. Operating any combination of these applications through a purpose-designed single architecture and software environment makes it possible to achieve the benefits of both a DCS and a PLC/SCADA system without many of the traditional downfalls of either. It is this seamless inter-operability that makes plant-wide automation systems so effective.

At the core of the PlantPAx is the single database that is used for the Controller, HMI, Historian, Batch Management, Asset Management and Business Intelligence Tool/Reporting Package. Any data created in the system is instantly accessible to all the software packages that need it and a single security model simplifies the management of user’s profiles.

The key principles behind this solution can help to drive a lower cost of ownership. Using a single architecture reduces initial engineering and integration costs. The process optimisation and business intelligence tools help to maximise plant efficiency.

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Expansion Advantages of Wireless Controls

Josh Thompson, principal, Point Source, says that wireless networks provide facility managers with a number of options to both save money and expand into areas they might not otherwise have been able to reach. After all, running a wire requires additional materials and a hole in the wall.

"The current cost of materials, conduit and cabling can push the BMS outside of the return-on-investment window. Wireless fixes that in many cases," Thompson says. "In an industrial facility, there are applications where sensors and controls would be desirable, but due to hazard containment, penetration of the hazard space is not possible. Wireless solves this problem."

That concept of reaching the hard-to-reach places also applies to security, says Gislene Weig, associate, Syska Hennessy.

"When they have a problem getting cable to certain locations and they want to put in a camera, then we would use wireless," she says.

There are additional wireless applications in security. RFID systems allow for tracking of inventory or equipment that isn't used in a stationary location. In health care, many maternity areas of hospitals have tracking bracelets that use RFID to ensure that babies stay in the area. If a baby is taken too close to the door, an alarm sounds.

Remote Control

If all you want in the way of remote access to building automation systems is the ability to log in after hours, that doesn't necessarily require a wireless system internally. But remote data collection on a real-time basis is another big plus of wireless systems, says Myers, using the example of a property manager in a multi-tenant building being able to pull electricity use data from a submeter by walking down a hallway, instead of having to enter individual units. Being able to leverage that real-time data is where the real payoff comes in.
"The applications where you can see return on investment would be in your energy management, your lights, your shades, your mechanical, your room on/room off times, your integrated HVAC and electrical scheduling, your peak power scheduling for operating purposes," Thompson says. "That kind of information, that kind of intelligence on the building that is not specifically life critical ... if properly integrated and commissioned, you can see huge ROI very, very quickly just in energy savings."

The growing use of wireless devices has produced, along with gains in flexibility and energy savings, some surprises for facility managers. In one building, Myers says wireless thermostats Velcroed to cubicle walls became a little too popular with staff who worked in the spaces controlled by the movable devices. When they were relocated, they took the thermostats with them.

" When they walked away with the thermostat, it lost touch with the zone it was supposed to be controlling and didn't do anything, basically," he says. "With a couple of these occurrences, they had trouble controlling the temperatures on the floor and couldn't figure out why nothing was working until they realized they were moving with the thermostats."

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The Greatest Impact On Automation And Controls In The Next Five Years

Software abstraction – Graphical system design is a great example how software abstraction increases the productivity of engineers and scientist from different industries and application areas.

 

Embedded processing – The ever increasing processing performance and the lower footprint of processors enables companies like National Instruments to bring technologies like multi-core processors into the industrial space and create off-the-shelf embedded systems that engineers and scientist can adopt for the most demanding applications.

 

Reconfigurable hardware – With shorter design cycles and increased pressure to innovate, reconfigurable hardware like field programmable gate arrays (FPGAs) provides the industry with a solution to create custom functionality with hardware performance without the investment and effort of designing an ASIC or custom board. Embedded in off-the-shelf systems and programmable with high-level design tools like NI LabVIEW software, these technologies are accessible for engineers and scientists with little embedded expertise.

 

The combination of a real-time processor, programmable logic and modular I/O within one system – National Instruments refers to this technology as RIO technology but we see a wide adoption for this concept in the industry.

 

Proliferation of Sensors - High-performance measurements are the key to solving sophisticated control problems and realizing robust systems. New technologies and the wide use of sensors in commercial products like smart phones or the Wii gaming console (and many others) have been increasing the availability of sensors and reduced the cost. This trend will continue and so we will see a proliferation of sensors in industrial applications.

 

Networking, synchronization and security – The increasing number of embedded and control systems used to solve today’s applications also increases the need for networking, synchronization and security technologies. And while there are a lot of different standards available today, the integration is where we expect a lot of innovation over the next couple of years.

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Automation Market of National Instruments Products

National Instruments provides products and platforms that enable engineers and scientists to design any system that needs measurement and control, using the graphical system design approach. In this effort, we design products that can be applied across many different industries and application areas. In fact, no particular industry accounts for more than 15% of NI revenue.

 

Industrial automation is of course an important element of the NI business and we have a lot of customers who are using our industrial grade embedded platforms to implement advanced control and monitoring applications; ranging from automated pipeline welding machines to building control and monitoring systems for turbines.

 

National Instruments will continue to invest in products and platforms that can be applied in industrial automation applications. The core strength of the NI graphical system design platform is the combination of productive software and high-performance hardware. In the industrial area these tools are especially beneficial for developing high-performance machines and devices that require advanced sensor feedback, are characterized through challenging control tasks or have quick time to market requirements. Because those kind of advanced applications often require integration into an automation process, National Instruments products can also accomplish lower-speed process automation tasks.

 

Like the PC and smart phone, most disruptive ideas combine existing elements in a way that provide a dramatically better solution. The same phenomenon is true for the smart grid. Embedded reconfigurable instrumentation and control systems powered by NI LabVIEW software are merging with cloud-based networking, analytics and other cutting-edge information technologies. The proliferation of smart networked embedded systems, widely distributed throughout the grid, will revolutionize the way electricity is produced, consumed and distributed.

 

Many of the industry leaders in smart grid technology around the world are using NI technology for designing, prototyping and deploying the embedded systems needed to transform today’s energy networks into smart grids. The Energy Summit at NIWeek 2011 brought in some of those experts to discuss challenges and solutions around smart grid technology.   

National Instruments has some powerful technology all centered around graphical programming using the company’s LabVIEW software. NI products are great for designing, prototyping and deploying embedded systems quickly.  At NIWeek there were many demanding applications demonstrated that were made possible using the high performance capabilities delivered by NI products.

 

Creating industrial control and automation applications is easy and intuitive using LabVIEW.  The drawback is that NI hardware and software has a high price tag compared to typical industrial control and automation products. National Instruments products are like driving a fine sports car - they are responsive and high performance, but expensive.

 

NI is supporting industrial communications with the most recent being EtherCAT.

 

In demanding industrial automation and control applications, NI products make sense for industrial automation and control.

 

I have been intrigued by NI FPGA based products since they were introduced, but they have been pricey. The newest FPGA controller offering is approximately $500 list price.

 

National Instruments is not a mainstream industrial control and automation product supplier. However, NI products are being applied in very high performance niche applications.

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Energy harvesting: a practical reality for wireless sensing

There are some very exciting high growth projections for wireless sensing for the Automation industry. More sensors mean more process efficiency, lower operating costs, lower maintenance costs, higher reliability, and greater safety. Wireless sensing provides the opportunity to install masses of sensors with virtually no cost of installation by reducing the need for cables carrying the signals from the field to the control room. Wiring costs can easily be 80%, or more in a hazardous area, of the total cost of installing a new sensor. Who wouldn’t like to get the same job for one-fifth of the cost or five times as many sensors for the budget? And it is not just the cost of the installation; there are many cases where plant has to be shutdown to facilitate installation adding another massive sum to the cost of new sensors.

Most of us routinely use wireless (cell phones, Wi-Fi) for communication, and the potential for machine-to-machine wireless communication is considered to be even larger. Wireless transmission of sensor data is now well established as a reliable method of monitoring industrial plants. It is even being perceived by some users as more reliable and maintenance free than hard wiring.

This whole new approach to Automation has been made possible by the convergence of new technologies:

• Low power electronics including microprocessors with sleep modes
• RF transmission systems that use digitally encoded signals (e.g. digital television and Wi-Fi) with an order of magnitude less power required than older analogue systems
• New energy harvesting techniques

So why is there so much interest in energy harvesting? Simply, you cannot get the full benefit of wireless unless the power source is also wireless. This means either a battery or some form of energy harvester. Until recently, the usual power source available to power a wireless sensor node or network (WSN) has been batteries. With their limited and non-deterministic life span, hazardous content, shipping and disposal requirements, batteries alone are not likely to provide a power source that will last the life cycle of the WSN application without maintenance intervention. The ideal solution is an energy harvester that is “fit and “forget” and will have a lifespan in excess of the WSN that it is powering.

What is energy harvesting? Energy harvesting is the extraction of usable energy (usually converted into electrical energy) from otherwise wasted energy available in the environment. On the macro scale (MegaWatts - MW) this includes hydro-electricity, wave power, solar panels, and wind turbines. However for wireless sensing, we are talking about harvesting immediately available energy such as vibration, heat, light, and RF energy to produce milliWatts - mW.

 
Power requirements for WSNs
Whether the power source is an energy harvester or a battery, it is important to minimize power consumption. Much can be done to minimize average power requirement; for example reducing reporting frequency. If a wireless system is being used for machinery condition monitoring, then it is unnecessary to specify the transmission of full vibration spectra every minute, when it is replacing a man on bicycle with a hand-held device who goes around once a month (provided it is not raining and he has nothing more urgent to do). Also parameters can be monitored and analyzed in the WSN, and it can be programmed to transmit alarm signals only when there is a problem.

To illustrate the issues, this article takes the example of a WSN that requires an average power of 3mW to compare various options. This is not untypical of either a frequent reporting requirement (such as several times per minute) or a high data requirement (such as complete vibration spectra).
The following table shows the theoretical life of standard sized cells from a leading Lithium battery manufacturer. In practice, the theoretical capacity is reduced by such factors as the need for intermittent high currents for RF transmission, self discharge, and low temperatures. Some newer designs perform closer to theoretical capacity and may include energy storage to help with the peak power requirements of WSNs.


Energy harvester power
So what are the options for energy harvesters to deliver 3mW? The following are systems available today, and they represent each of the main types of energy source that can be used in practice in many types of plant and other machine applications to provide the required power. Each of these uses a source of energy readily available in many but not all applications. However, with this choice, it should be possible to select a suitable device for the vast majority of applications.



More info here.

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CP1E smaller Omron PLC

New design. For small PLC Omron. To achieve the desired result with a shorter time and cheaper cost. Of experience and learning to truly Omron developed a new concept to develop products that focus on simplicity and economy but also its readiness to continue for the future.

Input and output prices were down. This is achieved using a high-performance chips that can handle high-speed signals at 100 kHz for the control of machines with speed and precision. Also equipped with high speed-output 100 kHz (in transistors) for the type of servo motor. Completely redesigned. The input / output of CP1E are cheaper compared to similar products.

An analog of the modern machinery to control the variable parameters in analog format. To activate other devices.

With a continuous output CP1E-NA20 (under the CP1E) packed into this capability without having to buy more. The analog resolution up to 1 / 6000 or 0.016% full scale resolution detail to cover most of it.

It has USB and RS232C with it has come to a USB port for connecting a computer to upload or download downloading program. USB cable is available in the market for the RS232C standard has a touch screen and whether the presence of an external load cell. Or used in SCADA.

To further expand in the future. Whether it be on a channel by using the expansion units 3 units or more channels of communication option board is required to choose a RS485/422A, Ethernet or RS232C.

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OMRON PLC - How to Use OMRON PLC Function Block

Function Block potential of our Omron CS / CJ PLCs for future projects. Our typical projects include the control of a few hundred devices (doors, intercoms, cameras, card readers, etc.). It is generally of PLC logic, just the same, except that they shall refer to various IO addresses.

Desrcibe The logic that is suitable for your project, you are perfect for Function Block processing.

If you and add a Function Block instance, copy the same instance will be labeled as you describe.
You can create a new copy by right-clicking on the Function Block and the change of the name.

However, it is quite possible the same instance in multiple copies Function Block Function Block reuse. But be careful that you do so only if the Function Block-code can be worked in, a single scan, so there are no timers, counters and data control statements, such as PID, which require multiple scans complete.
So if you Function Block contains only simple functions the same conductor Function Block instance can use and saves space. If your case requires separate Function Block user, you can still edit and update all at once through the internals of Function Block Function Block invocations.
You can find Function Block to authorities under the symbol table data type “Function Block”.
For more information about Function Block, see the “CX-Programmer Operation Manual Function Blocks Structured Text” that are found in the CX-Programmer-folder in the Start menu.

I have a love-hate relationship with building blocks. In my experience:

Function blocks are good for:
1. Mathematics (transformations, scaling, floating-point calculations, etc.)
2. Loops (I find it much easier to code loops in structured text)
3. repetitive tasks such as door logic, logic cylinder, stop logic, etc.

Function blocks are bad because:
1. too much memory
2. adds scan time
3. difficult problems if you do not know how Function Block does
4. to test more work ahead and to document
5. can be dangerous if you try to get online editing and “accidentally” change all instances of the block

The newest and latest CX Programmer Version 4 CPUs possible Function Block can not be created / edited by online processing.
CPU version 4 function blocks can be processed online, but it can not be created (from scratch) online.
CX Programmer 7.0 or higher is required for this function.

The indirect nature of the programming can be very powerful when you get your head around ..
Just a little something about Function Blocks with Omron PLC:

Look in the PLC memory usage on the “View / See Memory (UM). Sorry, but I’m in the Cx-P Spanish!
Sometimes, when large Function BlockS (ie, floating-point calculations), or simply to build only Function Blocks Omron (as Mechatrolink or DeviceNet), the PLC CJ1M become small and it must be greater than PLC (CPU43 or higher).

Function Block is a good tool to typical problems of copy and paste causes the programming to avoid if you need more time in the same routine, order, or steps, but conscious memory (EMS) are!

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