Good Reference Material on DCS 3

[jimgineer]

Can anyone recommend some good reference material on DCS systems? I don't encounter them a whole lot in my current position but would like to learn more. I need something that's both introductory, has many applications to look at, and hands on (I learn by doing).

Thanks-

 

[7anoter4]

Try at first this:

http://en.wikipedia.org/wiki/Distributed_Control_System

 

[ScottyUK]

You could start by having a look at the likes of Foxboro's I/A platform and Emerson's Ovation and Delta V platforms for some idea of what is currently on the market.

http://ips.invensys.com/en/products/autocontrols/Pages/AutomationControls-P017.aspx

http://www.emersonprocess-powerwater.com/ovation/

http://www.easydeltav.com/

----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[jimgineer]

I am also curious what importance you would ascribe with your understanding of the OSI model with various communication standards, etc. For those of you who are familiar with DCS, HMIs, PLC programming, etc... Did you come to learn simply through experience, or did you take a very structured and disciplined approach to the organization of what you know through the study of things like the OSI model? I am starting to run across plans for communications diagrams (showing how HMIs communicate with other devices like PLCs etc through modbus) and I want to make sure I take the right approach to learning this stuff, not haphazardly just throwing myself into it..

I did look into wikipedia which as always seems to give a good introduction to a subject. However as with anything that is worth knowing, the when it's used and for what is a much different thing than really knowing how to use it. Both are important, but I found wikipedia to be the former, and I need that as well as a structured approach to learning this stuff.

 

[ScottyUK]

You learn more about it when you are surrounded by bits of one that won't work than you ever will in class. That said, a good taught class is invaluable but, for me at least, ideally follows after you have some practical experience. Introductory classes tend to be too basic especially considering their cost, while advanced classes by their nature require need prior knowledge. OEM training on DCS is very expensive and there is little in the way of third party providers unlike the PLC world.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[jimgineer]

So there are OEM DCS manufacturers, and engineers which specify and design/use them?

How does this work usually get divied out, in terms of project management, by industry?

 

[ScottyUK]

Power industry...

DCS tends to be a single-source OEM product. Yes, there are design, applications, field ops, development, sales guys who exclusively do DCS work.

Normally an EPC contractor will award a contract for the major automation of a plant to a DCS manufacturer, possibly including within the contract a requirement to integrate small skid-type modules having their own PLCs into the DCS.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[jimgineer]

I see.

In a case where there are PLC/DCS folks and other EPC firms involved..

Is the main info that people need to know essentially whatever data or information is being communicated?

ie: I suppose the overall goals of the DCS system are established --- what systems it needs to control, HMI points, etc, and then what information it needs to communicate to any other systems that are being designed in the project, and the interfaces that they communicate with?

I remember the epiphany when I learned about how the architect (when prime) pays for the MEP/FP engineers, which helped me understand where work actually comes from and the flow of info on a project... I'm hoping for something like this epiphany in the EPC/DCS/SCADA/ etc environment.

 

[jimgineer]

I'm sorry too, forgot to ask - what do you mean by 'skid type modules'? I'm not sure I am familiar with this terminology or equipment.

 

[ScottyUK]

Skid-type module: a self-contained packaged unit with a specific purpose, supplied pre-assembled and tested ready for hook-up to the process. They're typical in the oil & gas industry and in fast-track power projects.

The typical DCS is a single-source system so the hardware is essentially pre-defined by the time it reaches market. The main areas where the engineering expertise is required are:

Designing the system architecture
Desinging the interfaces to the process
Designing the interfaces to third party equipment
Designing the application software
Designing the operator interfaces
Designing the engineering tools

Companies like Emerson and Foxboro would like to sell the EPC contrcator a full automation package, everything from valves and transmitters through to the DCS. I like products from both vendors but neither has the best solution for everything and I'd rather see the equipment chosen to best suit the prupose rather than to make life easy for the EPC buyer.

Contract-wise I don't think it is much different to what you already know, except in scale: whoever wins the overall contract will let subcontracts for work outside of their expertise. Normally power the EPC contractors have a background in either heavy civil works or are the turbine-generator OEMs, and maybe a few of the really big utilities will keep it in-house.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[jimgineer]

Thanks ScottyUK; that does help.

So in a case where a major EPC company has a contract to complete work, there are transducers scattered around a plant and they sub out to a DCS expert, would the DCS expert generally perform the actual labor for running their field interconnect wires and control runs, or would they generally do the design and communicate to the EPC firm about where they need connection points?

Same question for a 'standard' (non design-build) project: Would an architect get an MEP/FP firm, and then the Electrical Umbrella would include whatever DCS or controls work was needed? And then on the building side, would the EC be responsible for subbing out a controls contractor who knew how to do the work?

 

[7anoter4]

Very, very interesting ScottyUK, indeed!

 

[ScottyUK]

Not at the prices the DCS vendors charge! On a big job there will inevitably be a site electrical & instrument contractor (often the same organisation) responsible for cable installation and termination who in turn may well have a subcontract cable gang for the grunt work (no offence). I'd expect the E&I contractor to hand over field-verified loops to the DCS contractor for commissioning.

The DCS contractor may provide his own engineering and liase with a local company for physical panel installation. They have their own ways of working - for example Emerson PWS based out of Warsaw use a Polish subcontractor for their panel building and installation while they provide the technical expertise. It is an arrangement which works very well, having experienced it a few times.

I really can't comment much on the MEP side as it's not my area - sorry!


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[vitzwaters]

scotty, new in practical field, abbrev are confusing, i always read your comments because they are helpfull.

vitzwaters, RSA

 

[ScottyUK]

Apologies for the abbreviations, vitzwaters!

E&I - electrical and instrument;
DCS - distributed control system;
MEP - mechanical, electrical, plumbing (from the building services world);
PWS - Power & Water Solutions.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[DSCprogrammer1]

Hello All,
who are familiar with DCS, HMIs Foxboro?
Please help me to do new Template for screens.
Thank you in advance.