PLC Reviews. And a comparison chart.

[JesperMP]

I think that if there is a serious problem about one brands IEC compliance then it should be noted. Then again, I never intended the chart to be so detailed or all-encompassing or even correct. Lets not try to put too much into this.

Regarding the IEC standard, I have a serious question: Why should I care about it?

Each his own preferences.
However, I see this coming with a certain un-avoidability. Sooner or later, you will find that to be able to bid on projects, you must agree to use IEC601131-3 languages.
When I started to collect all the information for the chart, it struck me most how much the IEC languages has spread.
Is this good or bad ? Personally I think there is more good than bad in standards.
If there is something to complain about IEC601131-3 it is that PLCopen isnt ambitious enough.

Does anyone actually use compliance as a positive or negative feature when choosing a PLC?

It is hypothetical. But IF I had to choose another PLC brand today, IEC Structured Text would be a MUST.

 

[Paulus]

I know this is getting a little away from the point, but I feel that there needs to be a distinction made between IEC compliance, and support for the IEC languages.

I believe (reading between the lines) that JesperMPs' original intention was to show which package supported what IEC languages, not whether they actually has PLCOpen certification (hope I'm right here Jesper?).

If the software has Ladder Diagram as one of its graphical programming interfaces, then it 'supports' at least one of the IEC languages (compliant or not!).

Just thought it worth mentioning...

 

[JesperMP]

I have been caught out. That is the truth. I didnt grasp the distinction between "Compliant" and "Conformant".
I think that to have an IEC language in the chart, then it should be at least conformant. However, if there is no official conformance list, then I find it very hard to make a truthful chart. I looked at the PLCopen site, but I cannot believe that the few brands with conformant languages that are mentioned can be the complete list. I also find it strange if it is OK to state "IEC61131-3" in connection with a product, and then it doesnt mean anything really.

It all reminds me a bit of OPC. Some OPC products are compliance-tested, and some are not, but most of the non-tested products are still OK I think (Rockwell RSLinx for example).

If possible, can people who know a PLC brand well, inform me to what level its IEC languages are, if any ?
I know, its a lot to ask, but I see no other way.

Btw, GeoffC, I cannot from that paper see what the problems with ABs IEC conformance is. Can you please help me a bit ?

 

[GeoffC]

Why should I care about it?

If you only use one make of plc, then you probably won't care. If however you or your company have multiple types of plcs, then you should care. If all those plcs were truly iec compliant then reading, writing or even understanding the code in one is similar to the others.
No I don't think the code should be portable, but the closer to the standard the easier for the programmer and the maintenance guy following, if there are different plcs involved.
As an example I regularly use the help file (for the iec functions) from one make of plc when using another brand of plc (two brands that are compliant)

 

[GeoffC]

I cannot from that paper see what the problems with ABs IEC conformance is. Can you please help me a bit ?

The differences between AB functions and IEC standard functions are vast. If the standard function exists it will probably behave differently (TON preset time PT replaced with .pre, Elapsed time ET replaced with .acc, output Q replaced with .dn)
Or the function exists but with a different name (OSR, OSF should be R_Trig, F_Trig)
Or the function doesn't exist at all ( most of the conversions )
Some of these difference may seem small but it all adds up

 

[JesperMP]

Pertaining to Beckhoff and foot note *7, they list 4 options for Windows CE HMI's.
http://www.beckhoff.com/english.asp?download/cx_ce_hmi.htm
I haven't used them personally, but they will supposedly run directly on the WinCE version of the CX prodict line.

I have been chewing a bit on this one for a while.

The thing is that the socalled "Target Visu" from 3S/Beckhoff looks like a revolution. The HMI editor integrates with the PLC programming software, and the endresult is a HMI that can either run on the CE device natively, as a Webserver on the CE device, or remotely on a Windows PC. At least that is what I understand from the sales blah.
But with that the good news stops. There is practically zero hard information to be found anywhere - apart from a few butt-ugly screenshots. And I have never heard anyone state that they use this solution in practice. So I am at a loss as what to write in the chart. It is either a joke, or it is the mother of all HMI solutions.

I do not plan to mention 3rd party solutions such as the ones from Zenon, QVis, MoviCon and Indusoft.

 

[Archie]

As for TwinCAT target visualization, I have not used it as a stand alone HMI, but I have used within the programming environment.

You can build simple HMI screens to do things such as display values, enter values, boolean buttons, and animation. It will not do advanced things such as database interaction. I would compare it to the functionality of a panelview.

The visualization editor is integrated with the programming environment. When you login, the HMI screens become operationable.

I find it extremely useful for maintenance aids. For example, I've built manual override screens that I did not want accessible by operators. A maintenance person can log into TwinCAT with the programming software, then go to the visualation (HMI) screens and use them as troubleshooting tools without the need to comb through the program.

According to Beckhoff, these screens can be exported to the target visualization runtime and run stand alone without the need to login using the programming software.

Here is a visualization screen that I built for maintenance to use. It has some animation, value display, value entry, and buttons.

Hopefully my explanation didn't make it more confusing.

 

[JesperMP]

Thanks for the feedback Archie.

You can build simple HMI screens to do things such as display values, enter values, boolean buttons, and animation. It will not do advanced things such as database interaction. I would compare it to the functionality of a panelview.

Yep. That is also how I understand it. What about such things as user-login, alarm messaging and logging and such ? Can you make animated graphics ? Does it appear to be a fully fledged HMI solution ?

 

[Archie]

What about such things as user-login, alarm messaging and logging and such ? Can you make animated graphics ? Does it appear to be a fully fledged HMI solution ?

I have used the animation to change x-y position, rotate, and scale objects based on variables in the PLC program.

There is some kind of security settings with 8 levels of user access, but I have not used it so I wouldn't be able to give specific details.

There is an Alarm Table component that can be added to the screens. Once again it is a feature that I have not used.

Maybe someone else can chime in that has used these features. It should be the same as CodeSys.

 

[JesperMP]

It sounds as it qualifies as a HMI solution. It will be in the next update to the chart.

 

[Brandon Snell]

And I have never heard anyone state that they use this solution in practice. So I am at a loss as what to write in the chart. It is either a joke, or it is the mother of all HMI solutions.

I am currently using the Beckhoff TwinCAT visualization for my project and would agree completely with the following comment.

I would compare it to the functionality of a panelview.

It is actually very useful but also very limited. We are switching from using PanelView 550's and Plus 600's to the Beckhoff line and have not found anything we couldn't do. Keep in mind that our application is very simple.

There is an Alarm Table component that can be added to the screens. Once again it is a feature that I have not used.

It should also be noted that certain features such as the previously mentiaoned Alarm Table are only available on certain processor models. For example, the Alarm Table is not available on the CX9000 series (the one we use). Also, there is suppose to be ActiveX support but even our Beckhoff Apps Engineer claims that they do not know how to make it work correctly.

 

[JesperMP]

It should also be noted that certain features such as the previously mentioned Alarm Table are only available on certain processor models. For example, the Alarm Table is not available on the CX9000 series (the one we use).

Oh-oh. I think that this disqualifies the Target Visu from being a fully fledged HMI solution. At least for the CX9000.
Thanks for the feedback.

 

[rPraveenkum]

Jesper

Add Guardlogix for rockwell latest and greatest PLC types , this gives safety integrated with normal function

new row has to be added to repesent it level of safety use for example controllogix can be used upto SIL 2/CAT 3 applications

 

[JesperMP]

I have posted an update to the comparison chart:
http://www.plcs.net/downloads/index.php?action=downloadfile&filename=PLC_Comparison_chart_2007_v5.xls&directory=Misc&

Will someone make the PDF without messing up the links ?Thank you.

rPraveenkum, I dont want to add "GuardLogix" as an individual PLC type. I think it as a variant of the ControlLogix in the same way as the Siemens S7-F PLCs are variants of the normal S7 PLCs. Integrated safety solutions were already ticked in the chart.

 

[aikona]

Will someone make the PDF without messing up the links ?Thank you.
QUOTE]

Hi

I tried openinig in excel and print with PrimoPdf but no luck
I then tried OpenOffice and got better result except that the link doesn ot want to wrapin the cell ( which is why its goes wrong in excel )

Have a look at it

Eric