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View Full Version : PLC-DCS interfacing.............


swapnil
July 25th, 2003, 10:14 AM
hi everybody,
i just wanted to know or get some knowledge about interfacing PLC ,,,
with EMERSON'DELTAV distributed control system.
i just want to know how to interface plcs with DCS systems(IF ANYBODY KNOWS THE SOFTWARE OF DELTAV PROGRAMMING,PLZ ADD ME IN YOUR BUDDIES LIST),where r these interfacing required.
JUST TELL ME HOW TO INTEFACE PLC WITH DCS SYSTEMS,,(any PLC) i just want to know about the ways in which i can do this.if any body has idea about anything related to this plz send me,


thanks
swapnil

BobB
July 26th, 2003, 01:39 AM
What communication system does the DCS use? OPC, Modbus, BACnet?
:confused:

swapnil
July 26th, 2003, 10:36 AM
the communication system in opc type,do u need any more details???

Steve D
July 26th, 2003, 11:58 AM
Swapnil

I am like you a newbe to Emerson DeltaV ( Ver 6.3.3) I know you can interface DeltaV with the following protocols:
Fieldbus ( naturally ) AS-i, Modbus, and DeviceNet. We have done interfacing with all the above except Devicenet...it is not playing nicely at this time. We will in time interface to AB control systems via DeltaV Devicenet. We will also use OPC application to interface to our RSViews.

DeltaV is much different than AB. The documentation "Books on line" is sick compared to AB documentation. However, we have a local vendor who works very hard to help us in the learning curve. I would suspect if your local vendor in India does not help...three 9mm slugs to the M5 controller may be your only option :D

Good luck

Steve

swapnil
July 26th, 2003, 12:20 PM
hey steve,,
what do u mean by
...three 9mm slugs to the M5 controller may be your only option
do u have any idea of using,programmimg DELTAV system??
i m just going through books online right now n trying to understand as far as i can,,in fact DCS is somewhat new to me,,,,
and about local vendor it's nearly immpossible to get and help.
thats why whatever i have to do, should do alone taking help online,
but i m happy there will be good friends like u to help me out....

Steve D
July 26th, 2003, 05:45 PM
Swapnil

I am sorry. I should be more careful with my English. 9mm slug to the controller was my weak attempt at humor. I was jokingly refering to shooting the DeltaV controller card with a 9mm handgun without good vendor support. I assume that is not an option. Lets continue shall we?

I am not any way close to being an expert but I do work with DeltaV and have some idea as to how it works. I am not in anyway a DeltaV programmer.....more a harware guy

First thinks first....what version of DeltaV are you using? What type of PLC are you tring to communicate with? What kind of data are you trying to exchange? ( analog, digital......how many data points? )

What kind of process is currently running in your DeltaV......explain what you know about the system so far. Can you look at DeltaV Explorer and see your network? How many controllers, operator work stations etc....I guess I want to know how big your system is presently. What are you controlling?

DeltaV uses a form of function block language. If you have never been exposed to it before it can look a little wierd. A nice way to get a feel for it is doing is to go on-line with a control loop via control studio. There values from inputs and internal blocks will show up in real time and maybe you can get an idea of how the loop was programmed, how the digital and analog numbers flow thru the blocks ...the thought behind the function block. DeltaV does do a fairly good job in books on-line to explain every function block. But the rest of "Books on line" are almost a waste of time.

Another tip, in DeltaV Explorer, right clicking the mouse shows almost any function you might want to perform from you present position in Explorer. I have had little success with the diagnose feature the system almost never tells me anything I can use to fix a problem..except that a problem exist. Unfortantely I already knew some problem existed or I would not be using Diagnose.

Hope this helps you get started. I promise no more wierd attempts at humor.


Steve D

BobB
July 26th, 2003, 09:03 PM
You will need to obtain an OPC server from your PLC manufacturer and then set Delta up as an OPC client.
beerchug

swapnil
July 27th, 2003, 12:22 PM
u asked this right????

First thinks first....what version of DeltaV are you using? What type of PLC are you tring to communicate with? What kind of data are you trying to exchange? ( analog, digital......how many data points? )

What kind of process is currently running in your DeltaV......explain what you know about the system so far. Can you look at DeltaV Explorer and see your network? How many controllers, operator work stations etc....I guess I want to know how big your system is presently. What are you controlling?

1.i got deltaV 5.3 version with me.

2.PLC i m trying to communicate is seimens 135u

3.digital more preferably.

4.we got 4 operator workstations configured properly with only one M5 controller.

now about our system,u asked how big is our system,to be frank with u,
myself is 20 year old college student, n in my college we have purchased this deltav system,upto todays position we don't have any system hardware connected to it,i mean we just have installed and configured the opstations and controller,with 2DI,2DO,1AI,1A0,1fieldbus card,and 1serial port card,thats it,no field device attached yet...we have this deltav system for study purpose and to make some simmulations..and small model like level control,flow controll,etc we r gonna implement so as to give idea of an idea how does this works to other student.

now from my part,i have been chosen by college to do project on interfacing PLC with this system.and its all,and i m working on it,
like this by gathering any kind of knowledge i can get,,,
i just want to learn it any how it seems to be more intresting for me...and if i get some more experienced friends like u i bet i will do it much faster,,thanks a lots,hope u will help me the same..

thanks bobB for showing intrest,i would like to know what does OPC exactly means? what is it??i have just heard of it,i will surely ask for it to PLC manufacturer as u said,but like to have some knowledge about it first...

thanks both of u...
swapnil

Steve D
July 27th, 2003, 03:30 PM
Does anybody know if a Seimens 135U will do Modbus?

Swapnil: You need licencing inorder to be allowed to use the hardware you bought. ( please NOBODY let AB know about this idea ). They are called DST's. Tags are sort of expensive. If you have that many application stations I suspect the University must have purchased or were granted some DST as well.

You have two types of network cards now Fieldbus (does fieldbus) and the Serial card can do Modbus. The Fieldbus card and fieldbus devices in DeltaV are real easy to use. We have valves, pH, flow, and conductivity transmitters hooked up to the fieldbus network and they work very well. You will like fieldbus. As far as communicating to a PLC.....my guess is that Modbus is going to be the right choice. I am unfamilar with your Seimens PLC....let see if anybody knows if it does modbus.

From your Pro-Plus station you can check how many DST's you have left to assign.....Look in DeltaV Explorer....Duncan ( the mascot ) knows everything!



Steve

swapnil
July 30th, 2003, 10:30 AM
i must apologise for not replying quickly,but the fact is for last 2 days i was in one industry where i saw messung nexgen 5000 PLC interfaced with deltaV system.

As u told they have also interfaced their plc using modbus and serial ports of both PLC and DELTAV.when I asked them how did they do this the person over there told they just simply used serial registers of PLC and DCS to exchange the data,he used PLC for controlling purpose and DCS to keep track on history events,thats all..

now my problem,
what do u mean by.........
1.( please NOBODY let AB know about this idea ).

2.From your Pro-Plus station you can check how many DST's you have left to assign.....Look in DeltaV Explorer....Duncan ( the mascot ) knows everything!

Again,right now there is no DST yet in use,and I think we have DSTs granted (device signal tag).but what exactly these DSTs are??
by the way,we have licences available for every station.

and one more thing we have seimens s5 100u PLC and not 135u,that was my mistake.

ducan knows everything means what?

as i got knowledge of using registers for this purpose,but still little bit confussed about from where i could get the knowledge these registers?

thats all for now,and if possible mail me at bravosatya@yahoo.co.in.
or we can continue our disscusion like this only..

just give me a hint how to do this job of interfacing (using modbus)
and i will do the rest succesfully,,thanks a lot.

swapnil

Steve D
July 30th, 2003, 05:07 PM
Swapnil

I have once again inserted a quip meant at humor and it is not understood. My mistake...I had early promised no more humor.
AB ( Allen Bradley ) is known for being a very high priced PLC. Emerson DeltaV has introduced a new angle....pay for the privledge of using a data point of input/output even AFTER you have purchased the card...WOW. I joking asked everybody to not tell AB about this...they seem to generate enough revenue without this DST scheme.

The explaination about swaping registers sounds like a modbus protocol....I think you are the right track.

The mention of Duncan....Duncan is the mascot...the stupid little man made out of pipes and regulator dials you see as DeltaV boots up.....he has some following here in the United States...

Licencing...not only do you need liciening for the application stations... you need licencing for every data point you use...want to turn a light on when the processor is running... you pay money for that privledge. You need some DST's just to make a few things happen. You can see how many "spares" you have in DeltaV Explorer.

I am not familar with Seimens 100u... you need to find it if it has the ability to use the protocol modbus. DeltaV has a serial card that will "do" modus.

Good luck
Steve D

swapnil
July 31st, 2003, 08:06 AM
i know who is duncan , but as u said he can help me to do the job further,but i don't know how??
where and how to see how many DSTs are left to assign???
but i think none of DSTs are assigned yet.

again one more think plz give me the guideline about swaping registers,just help me by telling what exactly u mean by modbus protocol,just think for a second that this PLC i have can allow use of modbus,but what to do ahead i mean something related to configuring serial card and plc etc....

thanks
swapnil