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  1. #40
    Join Date
    Dec 2006
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    Hartford, Connecticut
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    442
    As far as daytime warm-up, when I worked for Trane the IntelliPak rooftop units did have an option for daytime warm-up which was a different function than morning warm-up. I believe it was only used on VAV heating units. If during the occupied mode the zone temperature dropped below the occupied zone setpoint (user adjustable) the RTU would transition to daytime warm-up. The unit would basically operate as a constant volume unit, all the associated VAV boxes would be commanded to full open, the VFD would go to 100% and the heating capacity would also go to 100%. When the daytime warm-up setpoint is achieved, the RTU would transition back to its normal mode of operation.

    I am pretty sure the setting can be disabled.

  2. #41
    Join Date
    Mar 2003
    Location
    NY
    Posts
    2,146
    Don't mean to hijack the thread but..... I believe the IntelliPaks ramp the VFDs to 100% for gas heat options. These require full air flow across the heat exchanger to prevent from over-heating therefor the output or relay to drive all VAVs to 100%.

  3. #42
    Join Date
    May 2002
    Posts
    9,564
    Quote Originally Posted by control$ View Post
    I'll agree to this about the ALC Bacnet to lon It's slow and it an it's a pain. But sometime's you can't rip out all the existing lon controls on a newer system. That always comes in time.
    Funny. My last one they ripped out the ALC stuff. Then only got stuck with one OEM supplied piece of equipment. From what I understand they will rip out this controller when the equipment leaves it's warranty period.

    I'd love to hear why the ALC bacnet implementation is superior to CEA-709 and IP852.

    Also, why ALC bacnet controllers are superior to other manufacturers if you would like to try to make those arguments.

  4. #43
    Join Date
    Apr 2007
    Location
    Amarillo by mornin'
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    853

    Does anyone else make it?

    Sysint,
    One question for you. Does anyone else make a chip that communicates LON not made by Echelon corp?
    "It's not that I'm smart, it's that I stay with the problem longer”
    Albert Einstein

  5. #44
    Join Date
    May 2002
    Posts
    9,564
    Absolutely. Yes.

    Question for you: Does any other bacnet manufacturer use ARCNET other than ALC?

  6. #45
    Join Date
    Apr 2007
    Location
    Amarillo by mornin'
    Posts
    853
    Who?
    "It's not that I'm smart, it's that I stay with the problem longer”
    Albert Einstein

  7. #46
    Join Date
    May 2002
    Posts
    9,564
    Loytec --- OK your turn on the ARCNET.

  8. #47
    Join Date
    Apr 2007
    Location
    San Diego, CA
    Posts
    1,330
    Quote Originally Posted by xarralu View Post
    Does anyone else make a chip that communicates LON not made by Echelon corp?
    The 8bit Neuron Chip is available from Toshiba and Cypress Semiconductor, or from Echelon Corporation (in the form of smart transceivers).

    32 bit chip designs utilizing the protocol are available from companies such as Loytec GmbH or Altera Corporation (Cyclone II/III FPGA on a NIOS II soft core).

    source: http://en.wikipedia.org/wiki/BACnet#LonTalk

  9. #48
    Join Date
    Apr 2007
    Location
    San Diego, CA
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    1,330
    Quote Originally Posted by sysint View Post
    Question for you: Does any other bacnet manufacturer use ARCNET other than ALC?
    I don't know of any other running BACnet on top of ARCNET, but here's a list of companies using ARCNET from their site:
    http://www.arcnet.com/abtarc.htm#applications

  10. #49
    Join Date
    Apr 2007
    Location
    Amarillo by mornin'
    Posts
    853

    HEY SYSINT!

    HA HA HA HA!!! You thought you had me!!! (Thanks DIGO) Just a little over 80 companies.

    Andover, Trane, ABB...
    On top of that I can move a jumper on my ARCNET and have regular MS/TP at 9600,19.2k, 38.4k, and 76.8k.


    Can you move a jumper on your LON and talk BACnet?

    My thing is SYSINT, you are right about ALC with LON behind in the times. They are now in beta with a LON portal that is supposed to be better than the SLTA-10 rig. I have not had too much trouble with the combo though. Once you know how it comes together its works.

    When I go to a job to do a site survey I'm crossing my fingers that it is either MODBUS or BACnet. I know 9 times out of 10 that if it is one of the two, there shouldn't be any trouble. I can even do a Discover Network and find the device(s) and see what going on.

    I guess we don't have much trouble talking to other BACnet equipment. In fact our guys prefer it if it has to be an interface.

    So out of the box, my LGR can talk MODBUS, Native BACnet, and our proprietary ARCnet.

    Why don't we all go back to good 'ol pneumatics and the we can start whining about if a one pipe system is better than a two.
    "It's not that I'm smart, it's that I stay with the problem longer”
    Albert Einstein

  11. #50
    Join Date
    May 2002
    Posts
    9,564
    I think his whole argument is destroyed now that he realizes the bacnet propaganda he has been educated with is not correct and actually the tables are turned somewhat realizing who is actually cornering a market with proprietary application.

    Answer to next question: ANSI/CEA-709, CEA-852 and EN 14908 Standard. ISO currently in process. IEEE 1473-L, IFSF, SEMI, and GB/Z 20177.1-2006, GB/T 20299.4-2006.

    Let's talk about the performance of CEA-709 twisted pair communication method vs bacnet MSTP and bacnet ARCNET.

    And whatever Sean McGowan tries to say, I would go with the opposite.

    Especially since bacnet plugfests are an absolute necessity, whereas this type of thing is completely unnecessary with CEA-709 networks.

    Personally, these guys have a hard time understanding structured variables. It's uncomfortable for them. They much rather single point of information at a time. Don't show them a SNVT_switch... they may run and hide. Why do you think they are so Modbus friendly? Same old same old.

    BTW-- Nobody is really using bacnet/arcnet other than ALC. Just because somebody is listed doesn't mean they are using it. Even if they were, tell me how they could put it on the ALC network. Digo doesn't help you there.

    Anyway, you can "discover" in a LON network too. Loytec can do it with their devices. OR you can use LNS which means that your software package can CONFIGURE other manufacturers devices. This is a capability that does not exist in the bacnet world to date. Further, they even have self-installing LON networks.

    "Can you move a jumper on your LON and talk BACnet?" -- In some cases yes and it doesn't need a jumper. I think you need to spend some time on the Loytec web site. Learn a few things. Anyway, if you have a far superior field bus that is a full 7 layer OSI (bacnet is not), why try to change it for some archaic data transmission method like bacnet MSTP unless you absolutely have to? Anyway, LON handles transporting bacnet, but you cannot do it the other way around.

    EDIT: Don't misunderstand me, I think ALC has some nice schemes and very nice visualization. My issues are the reality of the capability and robustness of the field bus. Further, I still give bacnet credit for a better application of AST functions as the Lonmark standard isn't really generally applied. However, in the LON world AST is somewhat insignificant as you can do it whatever way you want, and even with multiple vendors products. The catch is you need another device to do it. Tridium and others seem to be able to get it done, so why should I complain? If I did I can simply add a different box.... problem solved.
    Last edited by sysint; 10-28-2008 at 10:59 PM.

  12. #51
    Join Date
    Jan 2005
    Location
    USA
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    1,453
    Quote Originally Posted by twisted pair View Post
    As far as daytime warm-up, when I worked for Trane the IntelliPak rooftop units did have an option for daytime warm-up which was a different function than morning warm-up. I believe it was only used on VAV heating units. If during the occupied mode the zone temperature dropped below the occupied zone setpoint (user adjustable) the RTU would transition to daytime warm-up. The unit would basically operate as a constant volume unit, all the associated VAV boxes would be commanded to full open, the VFD would go to 100% and the heating capacity would also go to 100%. When the daytime warm-up setpoint is achieved, the RTU would transition back to its normal mode of operation.

    I am pretty sure the setting can be disabled.
    Yes it can be disabled and should be on a HW system or when the vfd goes to 100% the boxes will not go full open and the rtu will shutdown on high static. I do not know if there is another mfr that does daytime warm up but you can use it if you use your jace to translate it into another point that HW can understand then you would have to tie in the hot water temp to protect from subcooling the space when hot water is not available. Its not that bad of a reprogramming job if it is necassary. We just disabled it, the building works fine without it, the hot water reheats are more than capable of heating the building with the normal box flow, besides that this particular site uses symetre as the front end which is way less freely programable than ax.
    "It's always controls"

  13. #52
    Join Date
    Jan 2005
    Location
    USA
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    Quote Originally Posted by digo View Post
    Being that I'm in San Diego, I can see why I wouldn't be needing a daytime warm up around here anytime soon. Morning warm up alone is rare.
    I'm curious though, I couldn't find anything about daytime warm up online... is this a Trane specific function?
    http://www.peci.org/ftguide/ftg/Syst..._9_Warm_up.htm
    Trane is the only mfr that I have found that uses this point. It would be handy to use in some instances but it would require a bit of programming to use. Would not be to hard just not necassary in this instance.
    "It's always controls"

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