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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Technology in the PLC

PLC has been developing the capabilities of simple form and transform the same price level ever. And the development of which will go on. What’s left to do and tons more or no less interesting question.

As a related technology. We conclude the development of PLC from the past to current and upcoming follows.

1) patterns of language use. Still can not say that it will not use the ladder diagram (Ladder Diagram), but the role of the function block (Function Block) is more or even a programming language (Instruction List), which will combine both possible. IEC61131 requirements or not.

2) The development of the ability of PLC to manage mobile devices that generate a lot more like a servo motor. Linear motors. Inverter. By either increasing the speed of mobile functionality to support fast and accurate. Development of special cards for specific actions. Software development or software package for ease of use. These things will become easier and more common in PLC new generations.

3) the support for a network which has become a standard already. Optimization with a reduced number of cables used in plant and machinery is a current push for network-level devices (Component network), such as DeviceNet, Componet, EtherCat the needs for communication of control and order. and management of production networks driven in control and command (Control network), such as Ethernet / IP Controller Link and so on.

4) speed development. Still significant. Response to changes in a timely manner of machinery, more and more intense. The high-speed machinery. Especially in response to a device Encoder, Interrupt input, High speed pulse, even high-speed analog channels.

May be more Development plc. If you are considering the purchase or invest any new PLC. PLC that you are interested or have developed?

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Solve CP1H R88D Servo Motor Controller

I work around a CP1H R88D servo with a pulse output 0 problem. All power settings are standard, except for the electronic gear ratio. The example is the Handbook of 2000 pulses per revolution motor set.
Fine adjustment of the drive car (one horizontal spindle).

I have the move to Omron (power) function block in the CP1H.
The distance between the CP1H and the servo is about 6 m (2 m). The drive is a Panasonic with brake and encoder (not absolute).


Two cases:
1. 2000 pulses is not a revolution engine, only about 3 / 4 2000 pulses also not equal to 2000 forward pulse times (by a significant amount).
2. The highest speed I can use and still move the actuator 100, although I keep hearing that the CP1H is capable of more. The CP1H seems not the problem. When ordered with a speed of more than 100, the power simply ignore the incoming pulse.

I’ve been through all CP1H/R88D manual and found no answers. Has anyone successfully ran a similar sytem? Anyone have a hint of things to look for?
The manuals never a PNP output to the PLC station in pulse mode. It seems that the manuals are to be desired. I found three departments, which called into question. Well, I’m looking forward to implement the same system with an absolute encoder - should be a breeze - right!

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Monitoring memory space in the PLC.

Often used in the PLC to consider that choosing which version to use the CPU will have enough space to run the program. The count is difficult enough to evaluate. Because the function of machines, each machine has a different way of thinking is difficult and complex simplicity. And do not depend on the number of I / O.
So if you find ways to estimate a cursory I can do it without writing a program in advance because the CX-Programmer. Can be simulated. (Must be a joint program with the CX-Simulator).

Steps to use.

1. When writing a program so close to actually work. Is enough to see the capacity of content from programs like the CX-Programmer Tools by going to the Cross-Reference Report or press Alt + x.

2. Press the button Generate.

Total UM status means that all memory of this PLC model.
Free UM status means that the available memory remaining space to tell the normal PLC programming in units of step.

3. Commands each command of the PLC. To use the same memory. Depending on the complexity of the computation of new CPU can see that each step of the orders at the end of Part Programming Manual.

4. Students. Cross-Reference Report in addition to more memory space, the rest of the PLC can also be sure that nothing of the PLC variable that is already taken some Used many times. This would be ideal to modify or add applications. Which can be selected Report type: Usage overview (which is pretty. It shows only the active variables) Memory area: Choose the type of variables to display.

5. And then press the Generate button, the program displays a report describing the use of memory out.

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History of PLCs

Today i have article that story in PLCs,Twenty-five years I was in my last year with Allen-Bradley PLC and a specialist and educator. I grew up with the PLC in 1774, the PMC. What a trip through the PLC-2, PLC 3, PLC 5, computer-based programming instead of a luggable terminal and a 10 MB hard disk for the PLC-3 GA module for remote data collection and programming remotely through the RM modules.

A laptop for programming (Data General) was more than $ 8,000. Hard drive space is outrageous expensive, and Windows will not be used. PCs were ahead, and programmers learned useful DOS software.
From 1977 to 1985 there was an enormous growth pattern that most had not imagined. Remote I / O, HMI, SCADA, and similarly, the PLC to the DCS world compromise. Servo Control was also available. Special keyboards set them up.
Bit-flipping was an art.

We had to do in ASCII module interfaces, and network modules with interfaces for mini-computers like the DEC VAX and PDP-11.

Some applications were too fast for the PLC, but not much. Everything was a good deal for the PLC and the companies and individuals.

In 1986 I founded my own company and am involved with the newfangled software arena. Life changes decision proved quite good.

ICOM, Tele-thinking, tender gray, Taylor et al. made DOS-based PC programming software. Moved to PC-based HMI and ARCnet came to town.

But what really changed since 1985? It depends on who you ask. Marketing vs Engineering is the battlefield, as hardware costs have fallen to the point of goods.

Let me table for the next month to develop a perspective on where we are and where we come from.

Applications that make use of automation changed, but some are not. The reasons for the use of automation, more enterprise-centric. This wish it was in 1985-it just was not easy to implement.

“Real time” a new meaning, so that access to data is crucial. It was, but the preservation of the data was primitive. OEMs developing and producing their own interfaces for the collection of data for customers. We just have easy access to such data today.


Electrician to resolve successfully the systems of fixed terminals. The documentation was found on the printed scale. Difficult to navigate, but they were successful.

Encoders, converters, control circuits and more linked (then and today) with special I / O. Today, however, there are I / O buses, remote I / O of something. Instead of treating a PLC data table for hiking or quantitative information, you get the data from the device. But the data is similar, yes?

At the risk has changed, old, I do not think much. ControlLogix is ​​no different than the PLC-3 from 1980. You can scan multiple cards to support redundancy, the use of special communication card, data collection and other languages. It is a remote I / O and remote programming possible in both.

Applications are available for client / server environments. Mainly based on UNIX, but they worked.

Then something really monumental happened changed the rules changed, the development cycle, and changed the operative work. This cycle / career change made changes, what we have today. We had the goods but few were in force.

The shift was monumental software. Windows 3.0, NT and IBM OS / 2 Presentation Manager creates a free-for-all. A small company called Wonderware HMI took over the company. Because it was so easy, PLC were targeted. Ethernet landed in the workplace, and ensure that each Ethernet PLC had to speak.

New and improved technology may not necessarily be a different function. get from 1985 to 2010 Oldsmobile Porsche both what you want. We want to buy different things with the data. This requires a number of different “things” and it’s slow, painful and not to the order indicated that to change much advertising.

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