What Would You Look for in DCS HMI?

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Thread Starter

Nagesh_Mysore

With PLC, user can select any HMI package. But in DCS, HMI is bundled. From end user perspective, what key functionalities and differentiators you look for just from HMI perspective alone.

Assume only DCS HMI is Go/NO Go decider (not a real situation, but..)
 
Tough decision, but some things to consider are...
<p>- Ability to create and execute scripts;</p>
<p>- Graphic object management: object libraries, establishing parent/child links etc.</p>
<p>- The size of the default object library: does the vendor provide a basic library to get you started?</p>
<p>- Available animations, or the ability to create custom ones;</p>
<p>- Intuitive flow control between graphics, that is, easy to navigate from one screen to the next;</p>
<p>- The quality of the display building package - does it feel like using MS Paint, or is it a powerful tool?</p>
<p>- "Security" features: login credentials, allowing/disallowing of read/write for chosen equipment control objects (PID, discrete devices etc)</p>
<p>- Not related to the software specifically, but some packages have limited screen resolution or a maximum number of displays that can be connected to one console.</p>
<p>- Licensing costs for each display.</p>
<p>- Remote desktop availability for thin clients, or supervisors</p>
<p>Those are some things to get you started. It would be best to phone a few providers to see if you can request a demo, or attend a conference. Here are a few DCS vendors (system): Schneider (Foxboro), Honeywell (Experion), ABB (800xA), Emerson (DeltaV, Ovation), Yokogawa (Centum).

Good luck!
 
This question is a bit strange. I wouldn't base my decision on which DCS system to use on the functionality of the HMI since they are all more or less the same.

Anyway, what I expect from an HMI is to give me a proper control over my equipment (well designed screens with easy access to sub-systems). I really hate HMIs where I have to go through 2-3 windows to start a motor or open a valve manually.

The screens should be easily modifiable. I never saw a perfect HMI, I always discover later that I need a pressure here and a temperature there. And I don't want to depend on the manufacturer to put them on the screen for me.

Then alarms. Active alarms should be easily available (always on-screen if possible) with the possibility to filter them based on modifiable criteria. Having too many alarms is as bad as having no alarms on the screen, operators will end up acknowledging them without even looking at the cause.

On top of that, it is useful when the HMI records the alarms for some time, a month or more. In case of a problem, it is easy to track it back, to see if it occurred before without digging through other archives.

As a final feature, I find useful to have the possibility to easily trend parameters. If I have a strange behavior of a temperature, for example, I find it useful to put it on a trend together with some other parameters and see how it varies depending on the change of the others. Just looking at the current value is not always useful.

Also, a historian for the main parameters would be nice, with easy to build historical trends and data export function, but most of the HMIs do not have this included and it costs some extra. Sometimes a lot.
 
I've worked at what I call "Large Facilities" with multiple operators and over 200 individual graphic pages.Even the best "Navigation" is tough for new inexperienced operator to find a pump in a hurry. Honeywell has a search bar window based on equipment number can be invaluable. Who else can do that???(without building it)

Good DCS HMI has been built on the lessons learned over the decades and quite often contain convenient "built in" functionality that is only possible on other PLC type HMI when you build it.

Honeywell HMI also has the ability to get "view only" window of controller logic code, and the best part.... a hyperlink to custom file like PDF of the specific loop wiring diagrams. All "canned" features from the HMI.

Some will argue that "flexibility" is better than "canned" My standpoint is even though I can build a calculator with the components and a breadboard, Id rather buy one.
 
S

Snrcontrolfreak

> With PLC, user can select any HMI package. But in DCS, HMI is bundled.
> From end user perspective, what key functionalities and differentiators
> you look for just from HMI perspective alone.

> Assume only DCS HMI is Go/NO Go decider (not a real situation, but..)

- Native alarming windows

- Native trending

- Strong Security

- Ability to lock user out of operating system functions

- Active-X etc. Embedding. / scripting etc.

- Access to visible logic / control drawings / code (calculations or programming logic)

- Visibility of values held by variables used in control calculation blocks.

- Ability to track logic flow.

- links to help files / control drawings / data sheets / P&IDs / Schematics etc.

- Seamless integration with Historian

- Platform independent remote monitoring function

- VENDOR SUPPORT!!!

- Quick Performance with graphics capable of handling a large amount of modifiers (Read more than 500 up to 1000) Yes that is common to go that high.

- Single point of engineering

- Obviously Multiple monitor support.

- Configurable Control Groups to separate one DCS into multiple control areas. (separating alarm and control areas)

- Integrated System Monitoring (built in alarms that monitors hardware health)

- Support for systems with more than 30 HMI stations.

- Network Redundancy

- Graphics designed such that alarms have high contrast to other objects.
etc. etc.

I'm not asking for much, but I have to maintain it daily...
 
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