12 ways to design a low cost scada system
TRANSCRIPT
- A PUBLICATION OF AFFINITY ENERGY -
12 WAYS TO DESIGN A LOW COST
SCADA SYSTEMTHINGS YOU CAN DO AS AN OWNER/ENGINEER
TO MAKE LOW COST SCADA A REALITY.
TABLE OF CONTENTS
Intro
Know the ultimate vision for your facility
Specify early and in detail
Say no to overspecification
Specify equipment with HMI web capability
Realize limitations of some integrators
Don’t assume built-in features are low cost
Minimize APIs, gateways, and protocols
Match SCADA solutions with suppliers
Use object-based design
Only map certain points
Keep your hands from getting tied
Bring system integrators in earlier
Conclusion
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INTRODUCTION
WHAT YOU SHOULD EXPECT FROM THIS EBOOK
Almost everything that makes SCADA expensive boilsdown to customers not knowing what to ask for duringSCADA specification.
There are plenty of things besides the hard cost(materials and SCADA software) that affect your abilityto get low cost SCADA. And they’re all things you cantackle ahead of time with some careful research anddecision-making.
This ebook is a cheat sheet of things to think about anddecide on before you talk to your systems integrator, toultimately make SCADA a little more economical.
KNOW THE ULTIMATE VISION FOR YOUR
FACILITY
CHAPTER ONE
WHAT’S YOUR VISION?
It may seem obvious, but you’ve got to begin with the endin mind. You want to have as much influence as possiblein the beginning, because once things are started, it’sextremely hard (or expensive) to change course.
Your level of influence is highest at the very beginning. Youare in the driver’s seat. You have the greatest ability tochange what your suppliers provide prior to contractsbeing approved.
You can influence your equipmentsuppliers or partners’ choice ofPLC or SCADA system. You canalso influence the choice ofnetwork hardware. Hint: Ethernetor fiber make connectivity easierand integration cheaper.
It all starts with a plan. You don’t necessarily need to knowevery detail about your future SCADA system, but youneed to be able to outline your ultimate vision for yourfacility and the various systems that support it.
NEED HELP DESIGNING A LOW COST SCADA SYSTEM?
SPECIFY EARLY AND IN DETAIL
CHAPTER TWO
HOW DETAILED IS YOUR SPECIFICATION?
I can’t tell you how many times I’ve heard, “I really wishyou would have provided Brand X PLCs instead of BrandY PLCs…” Instead of specifying the brand they want in thebeginning, owners end up paying for us to rip out whatthey failed to detail, and start over. Or they live with whatthey have, but end up paying more for integration downthe road.
I’m not saying you can’t make minor changes along theway, but big changes can end up nearly doubling originalcosts.
As an integrator, the specification is ourBible. We’re always on the hook toprovide what’s in the spec. That’s whythe more detail you can provide in yourspecification, the better.
One of the most expensive parts of many SCADAintegration projects are change orders. The reason changeorders exist is because the customer/owner/engineerdidn’t provide enough detail up front, or didn’t outlineassumptions clearly.
SAY NO TO OVERSPECIFICATION
CHAPTER THREE
DO YOUR ENGINEERS CUT & PASTE?
We live in a cut-and-paste world. Unfortunately, we findthere’s a tendency for engineers to use cut-and-paste orboiler plate specifications. This can end up costing theowner more for features he isn’t planning on using in hisfacility.
To save time, engineers may cut and paste a 10-pageSCADA OEM data sheet that lists 20 different systemfeatures. Even if the facility only needs four of the 20features, the owner ends up paying for all 20 because theengineer is too lazy to write up the specification himself.Or he’s too busy to talk to the owner to dig deep and findwhat makes sense in their individual environment.
Further, cut-and-paste featuresmay force you into a particularplatform that costs more thananother vendor’s solution thatwould more than meet projectneeds.
Key to a low cost SCADA system, is tailoring aspecification in terms of what you need to operate yourfacility. Specify only the functions absolutely required.
Make sure you review specifications, preliminarysubmittals, and data sheets. You need to understand whatyou’re paying for. If you see something in there thatdoesn’t quite fit, question your integrator and engineer.
The good integrators work with you ahead of time toensure they adapt the specification to your unique andindividual facility needs. They may even question yourspecification when something seems out of place orunnecessary, helping you achieve that low cost SCADAsolution.
SPECIFY EQUIPMENT WITH HMI WEB
CAPABILITY
CHAPTER FOUR
CAN YOU ACCESS YOUR HMI ONLINE?
One of the biggest concerns in smaller projects is effortduplication, which represents significant cost.
“If the OEM already developed graphics on my localcontrol panel/HMI/OIT/smart display for a piece ofequipment, why should I pay additional cost for a systemintegrator to duplicate those same graphics in SCADA?”
Other than having an overall SCADA system with oneconsistent look and feel, some believe there’s no benefit.
Luckily, there’s a way to avoid graphic duplication.
If the local HMI is built with theability to view it in a web browser,a system integrator should beable to host that HMI within aframe inside a web-basedSCADA system. This completelyavoids duplication and lowersdevelopment costs.
There is a tradeoff, however. Graphical consistency withinthe SCADA system can’t really exist, because you’reencapsulating multiple OEM graphics into one system. Ontop of that, the system integrator will design brand newgraphics for devices that don’t come with built-in HMIs.
Here’s how you get a good tradeoff between the two:
The system integrator graphically designs a high-levelview of the system (e.g., the overall P&ID). The SCADAsystem can talk to device controls and only extract pointsthat need to be alarmed and trended on for that overviewscreen. When the user needs to drill down into the details,the system brings up existing OEM HMI frames. Thismaintains an overall common look with consistent trendingand alarming, without spending time duplicating graphics.
Moral of the story is, it helps to mention if HMI technologyfrom your equipment is web-based in your specification.
REALIZE SOME INTEGRATORS MIGHT NOT HAVE YOUR BEST INTERESTS AT HEART
CHAPTER FIVE
DOES YOUR INTEGRATOR QUESTION THE SPECIFICATION?
If an engineer specifies 10 items, some integrators provide10 items without question…even if it’s obvious thecustomer doesn’t need them. After all, the more heintegrates, the more revenue lands in his pocket.
At Affinity Energy, we view our projects as long termpartnerships. Sometimes, providing the best value tocustomers means we reduce the scope of what we couldpotentially provide. But the long-term benefit is a morecost-effective project. A closely-tailored project goes a longway toward building future trust.
You won’t always deal withsystem integrators whoquestion your specification.Especially if it means reducingthe scope of supply (aka, theirrevenue stream).
Unfortunately, integrators whoaren’t motivated to provide youthe best system are out there.
DON’T ASSUME BUILT-IN FEATURES
PROVIDE THE LOWEST COST
CHAPTER SIX
DO YOU PURCHASE ADD-ONS FROM YOUR SCADA VENDOR?
Some SCADA software is priced modularly. A few classicexamples are reporting, alarm notification, and historianmodules.
Often, the assumption is made that if you’re alreadybuying a SCADA system from a SCADA vendor, it’scheaper to also purchase all add-ons from the samevendor.
Actually, some SCADA vendors don’t offer economicmodules. In fact, they may be extremely poor quality andrun with limited functionality. Some providers realize theirown reporting, historian, and notification software is sobad, they drop support.
The good news is, there are plentyof widely supported, cost-effectivesolutions that don’t come from theOEM. Canary Labs’ Data Historiantalks to SCADA systems usingcommon APIs. For reporting,many integrators use DreamReport. For alarming, werecommend WIN-911.
MINIMIZE APIs, GATEWAYS, & PROTOCOLS
CHAPTER SEVEN
DO YOU USE MULTIPLE PROTOCOLS?
APIs, gateways, and protocols all introduce new costs tothe SCADA project you may not have thought about.
First of all, do yourself a favor and move away from serialprotocols. As an outdated technology, serial protocolsrequire a gateway device in order to bring devices onto acommon SCADA backbone. Gateway devices become justanother line item on a bill of materials that increases costto a SCADA project.
Secondly, the more protocol complexity you introduce intothe system, the higher integration costs will be for fieldstartup and verification.
HOW LONG DOES SCADA INTEGRATION
TAKE?
Nowadays, there are probably a dozen open protocols inthe industry. Some SCADA manufacturers give you allprotocols, and some require you to purchase eachprotocol as an add-on. Protocols also require drivers, yetanother cost.
The fewer number of communications protocols you baseyour system on, the lower your cost should be.
Make sure when you write yourSCADA specification, youspecify the APIs required totalk to your existing equipment.If you want a WonderwareSCADA system to talk to yourcurrently existing SAP workorder management system,what protocols will they use toexchange information betweenthe systems? ODBC?XML/web services? Knowingthis upfront will help integratorsestimate the correct number oflabor hours it will take to getthose devices talking.
NEED HELP DESIGNING A LOW COST SCADA SYSTEM?
MATCH SCADA SOLUTIONS WITH
SUPPLIERS
CHAPTER EIGHT
DO YOU HAVE DEVICES WITH BUILT-IN SCADA?
Large devices you purchase for your project might alreadyhave a mini-SCADA system built in. Although this seemslike an advantage, it can actually represent additional costif the SCADA system doesn’t match the overarchingSCADA system you specify.
To maintain low cost SCADA you have two choices, eitherget suppliers to use the same SCADA solution as yours, orrethink the SCADA system you want to use.
This scenario recently came up on a biogas project. Onepart of the biogas plant is a small gas refinery. Cleaning upgas before it’s put into the pipeline, the refinery is onesmall process within the overall biogas plant. The gasrefinery supplier provides a Citect SCADA system withtheir product.
Because the rest of the processes throughout the plant donot come with a SCADA system (pumps, dryers, mixingstations, etc.), the owner specified an overarchingTrihedral SCADA system. He wanted a single pane ofglass, one view into the whole biogas process.
Luckily for us, Citect andTrihedral both supportOPC communications.Our ability to exchangeinformation back andforth between therefinery and enterpriseSCADA system waseasily doable. We werefortunate.
Unfortunately for manyprojects, this scenariocould have played outquite differently.
The owner had already committed to the gas refinerysupplier. If the supplier’s provided SCADA system hadn’tbeen able to talk to Trihedral, there would have been anadditional expense to figure out how to connect thesystems together.
USE OBJECT-ORIENTED DESIGN
CHAPTER NINE
DO YOU PLAN ON EXPANDING YOUR FACILITY?
You can avoid reinventing the wheel by ensuring yourintegrator designs your SCADA system with object-baseddesign. Object-based design is based on reusabletemplates.
Using one common language, similar equipment, andstandard layouts, integration is broken into smaller, easily-managed blocks quickly and cheaply added through acookie-cutter approach.
By making and cloning a template for each device, (e.g.,meters, generators, UPS’, controllers, CAHUs, pumps,etc.) only minor changes are required to accommodatechanges between actual devices. By using a templatedapproach, standardizing a function across an environmentbecomes extremely simple.
Object oriented design is also an obvious choice forscalability reasons. In the future, if you were to buildanother facility, expand your current facility, or build asimilar process, you wouldn’t pay for non-recurringengineering. You already made that investment withobject-oriented design. All you’d have to pay for is theactual deployment of templates you had developed in pastprojects.
ONLY MAP POINTS YOU’RE ALARMING,
TRENDING, OR REPORTING ON
CHAPTER TEN
ARE YOU PAYING FOR EXTRA POINTS YOU DON’T NEED?
The number of points greatly influences if the system willbe a high or low cost SCADA system.
Unlike you might believe, not all data points need to orshould be part of your SCADA system. A meter, forexample, measures phase currents, phase voltages, andharmonics. These are crucial values to consider whentroubleshooting, but on a daily O&M basis they provide novalue. Instead, those data points should be accessed ondemand using the meter or the device’s proprietarysoftware when necessary.
Some instruments and devices(specifically metering, protectiverelays, and intelligent electronicdevices) come ready to integratewith a significant amount ofpoints. However, not all pointsare important to each owner.
It’s all about what information youneed to run your facility.
Our experience has shown that when we turn systemsover to owners, the owners use far fewer points thanengineers specify. We see too many cases whereengineers haven’t spent enough time with the owner, andoverspecify the points list. Their CYA approach comes witha cost.
Remember: capture only the points required to operateand maintain your individual facility.
10 REASONS TO UPGRADE YOUR SCADA
SYSTEM
KEEP YOUR HANDS FROM GETTING TIED
CHAPTER ELEVEN
ARE YOUR SYSTEMS PROPRIETARY OR OPEN?
When determining how to get the best bang for your buck,you’ll not only want to anticipate current needs, but futureones as well. Initial choices you make now can actuallymake the price go up exponentially in the future if you planon expanding. Often, if you spent a little extra money upfront, you save tens of thousands in the long run.
At Affinity Energy, we turn over all aspects of SCADAsystems we provide. Our customers have the ability toreuse what’s in their SCADA application, build upon,enhance, and share what they’ve purchased. Even if theychoose a different integrator, or decide to work on itthemselves.
One of those choices is ensuring youown the intellectual property you’repaying the systems integrator todevelop. Some integrators like to holdcustomers hostage with proprietarysystems and software. If the customerwants to make adjustments in thefuture, it ensures only that particularintegrator can do the work.
BRING SYSTEM INTEGRATORS INTO
THE DESIGN PROCESS EARLIER
CHAPTER TWELVE
WHEN DO YOU BRING IN A SYSTEM INTEGRATOR?
SCADA is viewed as supervisory. After all, the acronym is“Supervisory Control And Data Acquisition”. Because agood SCADA system should never be in the critical path ofcontrols, most engineers and owners don’t think it’simportant for systems integrators to be involved early on inthe design process. Therefore, SCADA doesn’t get asmuch attention on the front end.
Often the process goes like this:
The owner has a scheduling meeting with thegeneral contractor
The general contractor then passes thatinformation to the electrical contractor
The electrical contractor passes that informationto the integrator
NEED HELP DESIGNING A LOW COST SCADA SYSTEM?
Not only is important information easily lost ormiscommunicated down the line, but the longer you waitbefore engaging a system integrator, the more things willbe set in stone. Workarounds or backtracks to completethe project the way it was specified racks up additionallabor costs.
Owners and engineers who aren’t familiar with specifyingand designing SCADA will always benefit from bringingsystem integrators into the design process earlier.
CONCLUSION
LOW COST SCADAIS POSSIBLE
The obvious trend threading through this list is theindustry tendency to overspecify. Whether throughgreed, poor attention to detail, or sheer ignorance, it’scosting the end-user.
In the perfect world, you should be able to trust yoursystem integrator to walk you through the best ways tocut costs.
By taking the time to understand exactly what you’repaying for, asking the right questions, and beingskeptical of cut-and-paste engineers, you should beable to find the right balance between low cost SCADAand helpful facility data analysis.
NEED HELP DESIGNING A LOW COST SCADA
SYSTEM?The information in this ebook isn’t conjecture. It’s
based off the 800 controls projects we’ve completed over the past 15 years.
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