siemens vs lonworks
Wow, you guys really know your stuff. Thanks for all the great replies but now I'm really a bit confused because all I know is Siemens and that's all I've needed to know to run my equipment. I don't know anything about Lonworks or Tridium or ........ I work at one of several colleges within a "district" of colleges. The head of all the facilities of all of the schools has decided that all of the schools must have a central plant with glycol chillers making ice at night and boilers will be centralized also. So with cooling towers, pumps, 500 ton centrifugals, control valves, etc. there will be a lot of critical equipment and the head guy has decided that my school is showing favoritism by adding more Siemens to our campus and therefore he is insisting that we go with Lonworks. He usually gets what he wants but my boss will be meeting with him soon and we have a chance to make a last pitch to "keep it Siemens". I'm pretty sure the head of facilities will get his way and it be Lonworks indeed. With Siemens I'm only worried about pricing after warranty although another problem with Siemens I recently found out is a lot of their guys aren't experienced enough.
So bottom line is I'll be getting Lonworks to control the central plant but I already have Siemens embedded all over my campus. I then won't have much control of what gets installed because they write "or it's equivelant" into the specs. Can anyone explain to me in simple terms how this might work and what are my are my options if I have say. Will Lonworks be an interface between my existing Siemens and some other BAS system. What does Lonworks do and what control sytems other than Siemens would they (the design engineers) be considering for the central plant. What in you guys opinions would be the best set up for my situation?
siemens vs lonworks
I mean will I be able to interface with Lonworks from my Siemens front end or will there be two separate front ends . I'm that with Lonworks I will have to have another front end.
"So bottom line is I'll be getting Lonworks to control the central plant but I already have Siemens embedded all over my campus. I then won't have much control of what gets installed because they write "or it's equivelant" into the specs. Can anyone explain to me in simple terms how this might work and what are my are my options if I have say. Will Lonworks be an interface between my existing Siemens and some other BAS system. What does Lonworks do and what control sytems other than Siemens would they (the design engineers) be considering for the central plant. What in you guys opinions would be the best set up for my situation?"
Lonworks is a protocol. Siemens has Lonworks devices. Their devices would work in a Lonworks network with no Siemens front end and vice versa. Think of Lonworks as all devices speaking the same language.
In a Lonworks network every device, including "front ends" are peer to peer. Vendors like Siemens add their front end which is not necessarily peer to peer.
Now you need a gateway (translator) to get data in and out from Siemens to Lonworks depending on how you do it. If you want to split a bit from Siemens you have a gate. Otherwise you use whatever means they already use to talk Lonworks.
If you keep your central plant separate, you would have a gateway to Siemens and that is essentially your "front end" interface. You could also have multiple forms of local interface on the LON network in the central plant. It would be up to you and optional.
What you want to do is look at Lonmark.org. Their are standards for ASC type devices (vav's, heat pump controllers, etc...) This means that from manufacturer to manufacturer variables are the same name and type to assist in consistency. Further, on your programmable controllers you can specify sequences of operation and also variable names and types you want so that you get very consistent bids. At Lonmark you can download the Army Corps LON specification and also the Lonmark specifications.
If you do this right you will have a high degree of control on what is installed functionally.
I'm out of your area so feel free to email me in the profile web site (info@) or use our online contact form and I can get you some information and contacts to get your head around this better.
You guys should look at what steafa(owned by siemens)now has avalible.Its tridium based and is mostly lon controllers and recently they have added lns plug ins to meet job scopes and they have also released bacnet compliant controllers which i belive are rebadged siemens controllers.But as with any control system the installing dealers experiance and performance is far more important than any brand,i wouldnt except any system that wasnt lonworks or tridium based.if they install tridium make sure you have the licensing set up so you are able to change service providers if your getting bad service down the road.
siemens vs lonworks
Thanks sysint for the breakdown on Lonworks. Ideally what I would want would be a control sytem whereas I can use my Siemens front end (since it's alread in place) to continue to control old equipment and the central plant. With Insight I would like to be able to have the same control over the central plant as I now have over my existing HVAC....to be able to modify and create new programming code, set TOD schedules, create and trend points, use my laptop to troubleshoot field panels, all of this through Lonworks by way of Insight? I've found that sometimes with programming code... a line of code will stop working, or a local point is ignored, or code needs to be written in a different way. Here's where I'm confused ...since Lonworks is a protocol...does it merely consist of software and not hardware/software. And since Siemens uses a token passing protocol....is the token passed through the Lonworks protocol to the field panels controlling the central plant. My Siemens network has a server and all of our existing Siemens hardware/software will be upgraded and there is talk of then dumping the existing fiber optic network that is now dedicated to my BAS and going ethernet using using the colleges' nework backbone and server. They say this will be much faster.
If I'm seeing this correctly then...I'm not going to have two different control systems (like Siemens and Johnson Control for example) but rather I will have Siemens talking to non-Siemens devices through the Lonworks protocol via Lontalk. Ok I'll check out Lonmark.org
all of this through Lonworks by way of Insight:
- "to be able to modify and create new programming code, ----- Probably not.
- set TOD schedules, YES.
- create and trend points, YES.
- use my laptop to troubleshoot field panels, YES.
You are getting warmer. There are a couple ways to integrate Lonworks. However, utilizing what is called LNS Lonworks will help you out if multi-vendor products are utilized. The reason for this is that most manufacturers make PLUGINS that can be opened in other manufacturers software. This allows you to not only control and monitor those devices, but also configure them without buying extra software. For most ASC (application specific controllers) like VAV's and heat pump controllers this makes it a cost competitive market. However, most vendors maintain their own software in the programmable market. Distech is one manufacturer that encases their programming language in a plugin (FREE!) Rumor is another vendor that has their programming language already as a plugin will offer it free also. Regardless, when having programmables you can still specify what variable NAMES and TYPES you want to see to be able to monitor and control them YOUR way. Possibly somebody can add insight here but I would think you have a separate programming application for Siemens controllers that are freely programmable but simply download code through it's network. Manufacturers with Lonworks controllers do roughly the same method.
You can utilize a gateway and still have your Siemens front end interface to a LNS network. You may need LNS based software (take your pick) to reconfigure or add to your LNS network, however, when you do that your gateway may need some reconfiguration for added and changed devices.
As far as a protocol, Lonworks is far more scaleable and modern than the Siemens method. The Lonworks network would do it's thing on it's side of the gate and your Siemens network can plod along token passing on it's side of the gate. Network speed isn't just the medium, it is also the method. You will find that a Lonworks architecture going from twisted pair wire to an Ethernet backbone will be fast enough for most applications and comparitively inexpensive. (see Loytec.com)
"If I'm seeing this correctly then...I'm not going to have two different control systems (like Siemens and Johnson Control for example) but rather I will have Siemens talking to non-Siemens devices through the Lonworks protocol via Lontalk." --- I would say this is a mostly accurate statement. And on your Lon network you may have various vendors products on the same
More on freely programmable controllers: You would probably have a separate software application that will connect to the central plant. (LNS based software---whatever vendor) If you use programmables that have plugins then that's all you need. Otherwise, you may need the manufacturers programming software and most will download/mod programs through the same LON interface the LNS software utilizes.
Anyway, spend some time on Lonmark learning about the network protocol, devices and variables, and I'd suggest poking around www.loytec.com to see what products they have made for Lonworks networks. Finally, the inventors of Lonworks is Echelon. www.echelon.com --- I'd look there also.
siemens vs lonworks
Sysint- Thanks for taking the time to give me such detailed information. Now I have a much better idea of what I'm facing and what to look out for as this project approaches. The central plant is in the design stage right now but there are also three new 4-story building coming in the next 3-4 years on my campus. I'm sure I'll be needing more advice from you as these projects develop. In the meantime I'll be checking out the resources you gave me.
Bobby m, chris, dave and everyone else thanks for your input.
IMHO you should seek out the best control contractor in the LA area for your chiller plant project. Call your peers from other schools, attend local ASHRAE meetings and find out who has a good reputation for service and support.
Selecting a product line that is available from multiple sources gives you some prrotection from being stuck with one company.
You have alreadly mentioned having a bad service experience. Imagine that your plant goes down on a 90 deg day and some Jr tech is sent to fix the problem...
On the software side consider that your project will require some complex control programming for sequencing, optimization, and failure modes. Make sure you are comfortable with whatever programming enviroment and tools are being proposed
For large plant control projects I miss the old AC-256 I/O boards (64 UI / 32 UO) The JCI NAE25 looks interesting for high point density projects.
My point is everyone on this forum could provide your school with a 1st class installation using any of the popular control systems available. Find that person for your project.
OEM's have a great deal of control with sequencing the product(s). However, it would be good to work with somebody decent, AND with products that another vendor can work with in case it doesn't work out.
I would recommend BOMA or other property management groups before trusting ASHRAE. ASHRAE is actually in the control business by their actions.
Hey Sysint, Thought you might like to hear this. The engineer we have been working with lately who also happens to be the local ASHRAE president. Actually prefers LON tremendously over BACNET not to mention proprietary setups. And he is adamant and vocal about it.
Originally Posted by sysint
Last edited by freddy-b; 02-17-2008 at 08:41 PM.
Originally Posted by freddy-b
You must have found one of the few ASHRAE engineers who can make his/her own informed decision rather than just following the herd!!!
When you talk, you are only repeating what you already know. But if you listen, you may learn something new. - Dalai Lama
siemens vs lonworks
I work for a community college and this whole central plant concept has been pitched to the highest level people by an energy project manager (Ameresco). Ameresco has been selected by the powers that be and they are running the whole show of design/build. Their engineers are designing the whole thing. I am one of two HVAC techs on site. They will build the central plant at no cost to the college and then the college will pay Ameresco back with payments over a 20 yr span from the savings of producing ice off-peak. If we could talk them into using Siemens then that would be the only control of the situation I could have otherwise they'll go with Lonworks and use whatever sub contractors they decide upon. I would imagine they will be looking to do everything as economically as possible. With the recent meltdown I had I had lost confidence in Siemens service techs because two techs spent about 12 days between and couldn't get a handle on the problem (field panels all over the campus were coldstarting and losing their programs and communication was so slow that automatic downloads would time-out before panels could be re-loaded). They were content to pull each of 23 field panels from the BLN and let me have no front end and everything standalone. The rationale was that in next few months we would be upgrading our system our new math and science building is built. However a third service tech was able to get everything back. It turned out to be a fiber problem. He installed a couple of High Speed trunk isolator/extenders, replaced a 4-port fiber hub with two dual port hubs, and split our network into two networks. So my confidence is back at least in this particular tech . It looks like it would be ok to have a Siemens front end with a gateway to Lonworks. But I won't have any say over who Ameresco uses for the control install.