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Thread: TCP/IP

  1. #1

    TCP/IP

    If you use TCP/IP as your main commmunication protocol does it make Lontalk and Bacnet mute points?

  2. #2
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    Huh?

    kontrol out
    "Open is as open does." - Forrest Gump
    "Can't we all just get a Lon?" - Garry Jack
    "BACnet: integration or interrogation?" - The Janitor
    "Open protocols? You can't handle open protocols!" - Nathan R. Jessup
    “What’s that? Aaa… open protocols? Don’t talk about…. open protocols? Are you kidding me? Open protocols? I just hope we can hardwire an interface!” - Jim Mora http://www.youtube.com/watch?v=U7fjDS0jKiE

  3. #3
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    Rather than type out a response, I have stolen a quote from BACnet.org that should help explain-

    For BACnet to utilize the Internet for communication, it must speak the language of the Internet known as "Internet Protocol" or IP. IP by itself is little more than an envelope with a "from" and "to" address and a place for a message within. For equipment to communicate on the Internet a second transport layer protocol must also be used. Currently there are two primary transport layer protocols, "Transmission Control Protocol" or TCP and "User Datagram Protocol" or UDP. TCP is a reliable connection-oriented transport service that provides end-to-end reliability, resequencing, and flow control. The TCP/IP combination works much like a telephone call: a connection is requested, established, and then bi-directional communication follows. UDP is a connectionless "datagram" transport service. It is used by applications that do not require the level of service of TCP, provide the same services, or that wish to use communication services not available from TCP such as multicast and broadcast delivery. Since the BACnet protocol itself provides for the guaranteed delivery of packets, resequencing and flow control, it does not require the use of TCP and therefore utilizes UDP.

  4. #4
    Here is the article that inspired my question, I also beleive that some of this may not be accurate. I do not beleive you need the neuron chip any longer to communicate within the Lonworks protocol.



    What are some of the advantages of using Internet protocols (TCP/IP) instead of BAS-specific protocols such as BACnet, LonWorks?
    TCP/IP Internet Protocols are…

    well defined.
    widely accepted.
    free. No single company controls them.
    Anyone can look up the standards and can choose from a long list of component manufacturers.

    Internet protocols are continually improved and benefit from research and development from thousands of companies across hundreds of industries. The amount of money in R&D for the Internet and Internet-related technologies dwarfs that in the building automation industry.

    Internet protocols allow building automation systems to cross industry boundaries and interface with a wide variety of other systems.

    Internet protocols allow separate systems and groups of components to share the same set of wires. This reduces the overall cost of installing and maintaining several systems.

    Internet technology is not limited to desktop computers. The term Internet Appliance is applied to embedded electronic devices that use standard Internet protocols. Internet appliances are small devices (like building automation system components) that have this type of Internet protocol capabilities built in them. There is a tremendous amount of research in this area. The vision is to have all of the electronic devices in the home and office communicating with each other and sharing information. Devices from different manufacturers will instantly connect and exchange meaningful data with each other.

    BACnet
    One of the advantages of BACnet was that BACnet was developed by what was supposed to be an unbiased committee. This is in direct contrast to standards like LonWorks® that are essentially dictated by a single corporation. In addition, BACnect covers the specific needs of the building automation industry.

    One of the disadvantages of BACnet has been that cooperation among the players has been half-hearted. There have been many releases of BACnet products that were not 100% compliant. True interoperability between these products and compliant products could not be achieved. This left consumers somewhat disillusioned. To address this problem the BACnet Testing Laboratories® (BTL) was formed. But this was not launched until the year 2000—13 years after the conception of BACnet!

    Another problem is that, in general, the technology behind BACnet is not comparable to the state-of-the-art networking technology found in other industries and standards. Part of this is due to the sluggish pace of the standards committee. To address this major shortcoming, BACnet/IP was quickly introduced after the initial release. The idea of BACnet/IP is to place BACnet packets over the Internet. But this was more of an afterthought than a primary design goal. And it only further muddied the already murky waters of BAS interoperability.

    LonWorks
    LonWorks® is a standard that was developed by the Echelon Corporation. From its’ conception, LonWorks® has revolved around the LonTalk® protocol and the company’s Neuron® chips. Unlike BACnet, LonWorks® was developed by and is primarily controlled by a single company. Until recently, any product that was LonWorks® compatible contained one of Echelon’s Neuron chips. This of course raises the question of whether or not LonWorks® is truly open. To have the entire standard placed at the mercy of a single company is not an ideal situation for many manufacturers.

    One benefit of the single-company philosophy is controlled interoperability. By having Echelon enforce strict implementation of the LonTalk protocol, LonWorks® products achieve a higher degree of interoperability between multiple manufacturers than does BACnet. But this is at the cost of soul-source components and licenses.

    Even though Echelon is the sole source for LonWorks, it has managed to get the LonWorks standard accepted as part of several other open standards. For example, LonWorks is an accepted part of the BACnet standard. But in practice, these two standards are rarely used together. Ira Goldscmidt [1] had the following to say about the inclusion of the LonTalk protocol into the BACnet standard:

    “The issue of including LonTalk as a LAN technology within BACnet was passed prior to the third public review of the standard in 1995. The alternative appeared to be a deadlock and potential appeal of BACnet by Echelon, which led to an observer’s remark that some committee members held their noses while voting ‘yes.’”

    References
    [1] Ira Goldschmidt, “Development of BACnet”, Association of Energy Engineers “Strategic Planning for Energy and the Environment”, November 1998.

  5. #5
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    Well I Computrols has all the answers to our needs...

    So are they are suggesting to use proprietary protocols over TCP/IP vs Lon/Bacnet? Do they use other open protocols over TCP/IP like XML/SOAP??

    TCP/IP just setup the connection, not define what or how the data is transmitted.

    Is the whole system connected via Ethernet even down to the unitary controllers?
    Propagating the formula. http://www.noagendashow.com/

  6. #6
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    I think you might be confusing the issue. BACnet is not analagous to IP. BACnet is essentially a language, which can operate of a couple different physical networks. One of those networks is IP based ethernet. If you are questioning why not just use ethernet for every device, instead of the MS/TP twisted pair, basically, it comes down to cost. CAT5 costs more than the single pair control wire. Ethernet requires a HUB/SWITCH based architecture, while MS/TP's daisy-chain approach is more in line with the way controls are distributed through a building.

    Ultimately... I'm not really sure what you are asking...

  7. #7
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    Maybe I'm misreading the kool-aid.

    Computrols is claiming we should embrace TCP/IP over bacnet/lon. Yet TCP/IP is nothing more than a means to establish a communications "channel". It does not spell out how data should be transmitted over that channel, which is where Bacnet/Lon come in.

    So this looks like nothing more than a marketing piece that is aimed at confusing customers / engineers so they can use proprietary protocols over TCP/IP, and claim its somehow better than a standard protocol that can be easily integrated.
    Propagating the formula. http://www.noagendashow.com/

  8. #8

    Confused

    I guess what they are saying is that the Lan is already in place so why run twisted pair thru out a 10 story building? What I am trying to figure out are they correct? I have been researching controls and by no means am I an expert. I don't see many other manufacturers using IP at the controller level, and is TCP/IP a true open protocol? I spoke with a Trend rep and he stated that in europe almost all jobs are done using the Lan or ethernet, and that it does not seem to be catching on here state side.

  9. #9
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    It would appear that the opinion piece posted above is more than a decade old and it seems to have been written by someone outside of the industry who doesn't understand what LON and BACnet bring to the table.

    Although I got a kick out of this term: "soul-source components"

    Makes me think this thread should be relocated to ARP. :-P

  10. #10
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    Quote Originally Posted by BACnet View Post
    Makes me think this thread should be relocated to ARP. :-P
    I would agree, having a hard time hold back on my true thoughts on this little piece.
    Propagating the formula. http://www.noagendashow.com/

  11. #11
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    Quote Originally Posted by BIGDICKMaGEE View Post
    I guess what they are saying is that the Lan is already in place so why run twisted pair thru out a 10 story building? What I am trying to figure out are they correct? I have been researching controls and by no means am I an expert. I don't see many other manufacturers using IP at the controller level, and is TCP/IP a true open protocol? I spoke with a Trend rep and he stated that in europe almost all jobs are done using the Lan or ethernet, and that it does not seem to be catching on here state side.
    There are two issues here- protocol and transmission medium. As a transport service, TCP & UDP are both used the world over, the reason BACnet went with UDP is laid out in my initial post above. TCP can't "replace" BACnet or LON or N2, etc. It's not the same piece of the puzzle.

    The second issue you are bringing up is the type of wire that is run through the building. MS/TP is not as fast a method of transmitting data as BACnet/IP. So from the outside it might look like there is a shift moving from MS/TP to IP, and to some extent that is happening. But the cost difference to install cat5 vs twisted wire is a massive one.

    Picture a building with 500 VAV's, a handful of air handlers and a few dozen other BAS components all tied together into the BAS. The air handlers, the front end, web servers (etc) are all likely directly on the IP network. The VAV's however are likely not.

    Picture stringing a twisted wire from VAV to VAV through the system. You've probably got 5 to 10 trunks throughout the building and each of them has devices daisy chained from one unit to another. If you changed the scenario and ran cat5 directly to every VAV, you'd end up with 100x more wire needed.

    In the MS/TP paradigm, there is one connection to IP per trunk, then two wires run from there to the first controller, two more wires run from the first controller to the second controller, two wires run from the second to the third and so on and so forth.

    In the Cat5 paradigm you need to run separate wires to each and every VAV controller. This means that not only do you need expensive 8 conductor wire, but you can't just hop from controller to controller. this is because you can't just splice into cat5, you need a hub or a switch for every single wire. The only way to daisy chain the wiring would be to add a hub at every VAV, which would double the cost of every VAV and would still force you to use the more expensive wire.

    So while there is a push to make more direct-to-IP devices, there is no desire in the industry to double or triple the cost of a BAS simply to be able to brag that you're IP through the entire system.

    *note- the 100x number was pulled out of thin air, but you get the idea.

  12. #12
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    I can't believe we continually feed the troll
    Quote Originally Posted by MatrixTransform View Post
    very soon it is you that will be pwned

  13. #13
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    Quote Originally Posted by BIGDICKMaGEE View Post
    is TCP/IP a true open protoco

    TCP/IP is a open standard, however it just sets up a communication channel.

    Analogy

    TCP/IP is like the phone company. You dial a phone number, they find the other end, ring the phone, and makes sure what goes in point A comes out point B and vise versa. The phone company could care less what is spoken between the points. This is what TCP/IP does.

    Now if point A is speaking english and point B is speaking setswana neither side is going to have a clue as to what each other is saying.

    This is where bacnet/lon come in. Both sides speak the same language and they can communicate.
    Propagating the formula. http://www.noagendashow.com/

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