Myths of LonWorks and BACnet

1 Building owners and facility managershave long awaited the means to breakthe proprietary lock of the buildingcontrol manufacturers. BACnet andLonWorks are two protocols that arecompeting to be the key that unlocksthe everyone is enthusiastic aboutLonWorks and BACnet . There aresome who want one to win at theexpense of the other, and there are afew who are still hoping against hopethat both will somehow disappear. So,amidst the hype and the claims there isalso accusation and confusion. Thisarticle represents a view of what is realand what is #1: It s a duel to the death -only one will be left so.

2 This myth often cites assupporting evidence the Betamax vsVHS knockout that occurred a fewyears ago. But the comparison is flawedbecause Betamax and VHS weremutually exclusive products, whereasBACnet and LonWorks products caninteroperate in the same and BACnet are competi-tors, yes; but they both have a place inthe industry, and they both have acritical mass of are even some building controlmanufacturers who are purposefullydesigning their product lines with ahybrid of BACnet and LonWorks astheir standard the four configurationsshown A is a design fromyesterday with an attempt to adapttothe industry standard, but not system is still proprietary, andover time will fade from the scene, orwill be relegated to specialty nichemarket applications where interoper-ability is not an B is maybe better,maybe worse.

3 It seems to have beendreamed up by a marketing depart-ment. It allows the marketeers to claim we have adopted LonWorks to allowyou, the customer, to mix and matchdifferent manufacturer s components. Sounds good, but what is left unsaid isthat the customer is still not free to mixand match different manufacturer other words, if the customer wantsto contract for an addition to anexisting system, he can only entertain abid from a competitor if he agrees touse the original supplier s proprietaryworkstation, and agrees to pay theoriginal supplier s price to reconfigureit for the new , with the original supplier sproprietary grip still in place.

4 Thanks a C begins to address theneeds of the customer. The customercan now interoperate differentmanufacturer s systems without beinglocked into a particular supplier, andcan mix and match different supplier scomponents (although at thecomponent level, it may not be as costeffective as it sounds). Myths of LonWorks and BACnet by Gerry G. Hull,President, Automated Logic CorporationConfiguration AConfiguration BTo express an opinion, Automated Logic has paid for the following D also addresses theneeds of the customer. The customercan interoperate different systems,andcan mix and match components (again,it may not be cost effective at thecomponent level).

5 Why would some manufacturerschoose configuration C while otherschoose D?There are as many reasons as there areengineers designing them,but from thecustomer s point of view,it probablymatters , LonWorks is not going awaybecause some manufacturers aredesigning LonWorks components intotheir product line,and it is very costlyto change later on. BACnet is notgoing away because it is the protocolof choice at the system level - not oneof the top building control manufac-turers has chosen LonWorks for thispurpose. If they are embracing interop-erability,as in configurations C or D,they are choosing BACnet to do #2: It s a lovefest - they areworking together in ,it is not a lovefest - they arecompetitors,remember?

6 Yes,they areboth chasing the same goal,interoper-ability. But within each group there area few who still believe in Myth #1,andwant their side to win. Pointed jabs inthe ads and hype are not vast majority of the members ofthe LonMark and BACnet groups,however,see the fallacy of Myth #1,and understand the need for bothgroups to work together. A workingrelationship exists today between thetwo groups,and it is getting better asthe reality sets #3: One is expensive, theother is for cost effectiveness abound,but the bottom line is there is nosignificant difference in the cost ofmanufacturing controls based on aproprietary protocol,the LonWorksprotocol,or the BACnet protocol.

7 Ifthere is a difference,it will be lost as arounding error on bid cost is the primary criterion,comparethe life cycle cost of configurations Cand D versus configurations A and s where the big bucks #4: One is complicated, theother is we go again. Some folks spendtheir time on this type of argumentbecause they still believe in Myth # and BACnet are both like anInternet browser - they are complicatedif you want to know how they work;they are simple if you want to knowhow to use #5: Specifying either one isa ,if you are trying to force acontrols manufacturer to interoperatewith a competitor through the specifica-tion process,when the manufacturer isnot committed (or when they arecovertly opposed to it),then it is indeedvery,very difficult and will likely resultin a nightmare.

8 On the other hand,if acontrols manufacturer is committed tointeroperability,and some are,then thespecification process is simpler than ithas ever you want interoperability,first spendyour time determining which controlsmanufacturers are committed andwhich ones are not. Then,use thespecification process to spell out yourperformance and functional require-ments. It comments are CConfiguration D