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Online Operations with ABB 800xA
Online Operations with ABB 800xA

Hello all,

I'm trying to find answer on question about online operations in ABB 800xA:

- Is it possible to download new version of programming code in AC800M without stopping of CPU. and, hence, interrupt of process (for example if I would like to add new PID regulator in existing application, or change some cyclic logic, or simply invert some bit in logic)?

- Is it possible to download new version of hardware configuration without stopping of CPU (for example, if I would like to add new module in existing slave, or to add completely new slave in control network, or simply change a configuration of existing module in Control Builder)?

Thanks.
Eugene

By Torulf Wiberg on 9 December, 2009 - 8:23 am

The short answer is yes, you can do that. However there are limitations to what you can do on-line with devices connected via Profibus DP.

/T

-------------------------------------------------------
Torulf Wiberg Tel. +46 (0)40 59 50 50
Deterministic Control AB Fax +46 (0)703 83 08 08
Derbyvägen 6E Dir. +46 (0)40 59 50 56
SE-212 35 Malmö
SWEDEN

Hello Torulf!

Thanks for your answer. In short yes - for my both answers? Even in non-redundant CPU's configuration?

Maybe you have some document which describes such online operations with AC800M? I read a lot of manuals regarding Control and IO and, if I understand right, it is possible to download only whole project (not parts of project) and while project downloads PLC is not executing, just holding last values of variables. Am I right?

Kindest Regards,
Evheniy

By Torulf Wiberg on 10 December, 2009 - 9:30 am

Evheniy,

Yes to both questions, even if non redundant.

The system will continue to execute during the download but, as Rob wrote earlier, there is a short period where the execution is interrupted as the CPU switches execution to the new image. I do not know the possible duration but in our application it is never a problem.

Regards

/T

-------------------------------------------------------
Torulf Wiberg Tel. +46 (0)40 59 50 50
Deterministic Control AB Fax +46 (0)703 83 08 08
Derbyvägen 6E Dir. +46 (0)40 59 50 56
SE-212 35 Malmö
SWEDEN

Hi Torulf,

thanks for your answer. Is it true also for AC800M controller and Control Builder M, without 800xA? On your site I see that you are working also with Honeywell products (Plantscape, HC900). May I ask you what is better, in short, for continous process and for continous + discrete process? Thanks.

Evheniy

The Standalone AC800M compact controllers are absolutely identical to those integrated into 800xA. The only difference is that the Compact Control Builder programming tool is slightly different from the 800xA version. All the PLC software is compiled and downloaded in exactly the same way.

The issue of exactly what happens when you download an Application to an AC800M controller is more complex than can be explained in a 5 line e-mail to a forum I'm afraid. Without going into detail, the "Stop time" (which is very short) will be less than a single scan of the application as long as you have enough free memory. The definition of "enough" is left for later. If you don't have "enough" the stop time will be a little longer. If your application is too big, it wont download.

800xA is one of the better DCS systems on the market, but whether its better for you is another question entirely. We are system integrators and like 800xA because we can develop, modify and commission software very quickly. But that's only my opinion.

Rob
www[.]lymac.co.nz

By Torulf Wiberg on 13 December, 2009 - 7:52 am

Evheniy,

The controllers behave very much the same with or without integration to 800xA.

Technology is only a little part of what is important when selecting an automation platform so I can not guide you. However, you are comparing two very different offerings here. The HC900 used with PlantScape (or today Experion) is not an integrated system. The Honeywell equivalent to 800xA is Experion PKS.

Good luck!

/T

-------------------------------------------------------
Torulf Wiberg Tel. +46 (0)40 59 50 50
Deterministic Control AB Fax +46 (0)703 83 08 08
Derbyvägen 6E Dir. +46 (0)40 59 50 56
SE-212 35 Malmö
SWEDEN

Hello Torulf!

Thanks for your answer.
Yes, you are right, Plantscape and HC900 are not comparable. One more yes, the technology is not biggest part when one is deciding to select the platform, at least for following couple of tenth years. Especially if one has no such distributed control system, just PLC+SCADA.
By the way, PLC+SCADA is not bad.

Kindest Regards,
Evheniy

By Nitin pulastya on 23 September, 2010 - 5:48 am

Ya, You are right, we can download the application after applying changes in hardware and software in controller and there is a short period of time where the execution is interrupted as my friend Rob wrote...but it depends upon our changes....as i have faced the same type of problems with AC800M-PM861/PM864 and that time our OPC server disconnect for a movement (3-10sec or more) but again it connects automatically.

We can remove/reduce such problem with proper programming planning.

I am working from last 4yrs on 800xA 4.1/5.0.2

Yes to both questions.

However, be careful when adding new Profibus devices to existing profibus networks. Be absolutely sure that your new hardware exactly matches what is installed on the profibus.

And often it is not such a great idea to disturb any bus hardware (not just profibus) by adding new devices with your plant running. It is best if you can do this while your plant is down.

You will get some warning messages about execution being interrupted when downloading changes to existing hardware. This stop will normally mean you might miss a single scan of some of your application programs as the change is made. Normally this is not a problem unless you have some extremely critical software that must never miss a single program scan.

Rob
www[.]lymac.co.nz

Hello Rob!

Thanks for your answer. I agree that better time to make constructive changes while maintenance stop of technology and not during production. But there are some situation when you need to do this.

What do you think, what are advantages of 800xA in comparing with other DCSs?

Thanks.
Evheniy

We have just commissioned three large 800xA systems and are in the process of cleaning up project punch list items. As such, online controller downloads have been literally a daily occurrence. As part of the process, we make sure that we go through the difference report in detail, inform operators, and put relevant control stations in manual. Note that the previous 3 items are something we do in older DCS systems also. Make sure that you do NOT check the "cold restart" option - stick with the warm download. After literally hundreds of downloads over several months, the online download process has proven to be very robust. I agree that hardware changes can carry the most risk. Most of my experience has been with adding native S800 devices, Modbus, and Foundation Fieldbus (FF) devices. Depending on what is changed in the FF configuration, downloads to singular devices being the most common, a download to a linking device might be required. In that case you need to understand the ramifications of an interruption of data flow to the related instruments.

Hello John,

thanks for your answer.

> As part of the process, we make sure that we go through the difference report in detail, inform operators, and put
>relevant control stations in manual. <

You did this steps just for any case because download process could not be successive?

> Note that the previous 3 items are something we do in older DCS systems also. <

Do you mean old ABB DCS or other?

I never worked with DCS. I just saw a couple of times what other people did with DeltaV (redundant CPUs MD+): they extracted master CPU from carrier, put new one on empty place (if I remember right this new CPU synchronized data with standby) and after all of this downloaded complete configuration into redundant CPU. During this no one operator see problems with process.

I do not have real PLC to see what does mean downloading process in 800xA so please excuse my too far meticulous questions - I just want to be sure that 800xA is the technology-friendly system and never interrupt whatever I will do. Of course, I will do without hammer :)

Regards,
Evheniy

>> As part of the process, we make sure that we go through the difference report in detail, inform operators, and put relevant control stations in manual. <<

> You did this steps just for any case because download process could not be successive? <

(In the past we have experienced some process "bumps" due to the change in logic, not due to the actual download process, so we put things in manual out of habit. Informing the operating staff and reviewing difference reports are just good practice.)

>> Note that the previous 3 items are something we do in older DCS systems also. <<

> Do you mean old ABB DCS or other? <

(Both ABB and other DCS and PLCs)

> I never worked with DCS. I just saw a couple of times what other people did with DeltaV (redundant CPUs MD+): they extracted master CPU from carrier, put new one on empty place (if I remember right this new CPU synchronized data with standby) and after all of this downloaded complete configuration into redundant CPU. During this no one operator see problems with process. <
>
> I do not have real PLC to see what does mean downloading process in 800xA so please excuse my too far meticulous questions - I just want to be sure that 800xA is the technology-friendly system and never interrupt whatever I will do. Of course, I will do without hammer :) <

(Again we've done hundreds of warm restart online downloads with absolutely no problems other than an occasional mistake in the logic itself. The "never interrupt" is in the hands of the person(s) implementing the change - and this is true for any system not just 800xA. There is no substitute for not doing the wrong thing. John)

Hello Torulf, Rob, John!

Happy New Year and Merry Christmas! Best wishes
for you all.

I'll be very thankful if you can share some project of 800xA version 5.0 with me. I did some test project with Function Designer as described in manuals (PID Loop 1T1FC1) but would like to see some professional work. May you help me?

I will understand if no.

Kindest Regards,
Evheniy

Hello Torulf, Rob, John!

What you can say about my request in last post?

Kindest Regards,
Evheniy

By Torulf Wiberg on 8 January, 2010 - 8:42 am

Evheniy,

Sorry but, because of company policy, I am unable to distribute application configurations.

Regards/T

-------------------------------------------------------
Torulf Wiberg
Deterministic Control AB
Derbyvägen 6E
SE-212 35 Malmö
SWEDEN

Hello Torulf,

I understand, thanks for the answer. May I send you an e-mails on your working address if I will have some questions?

Kindest Regards,
Evheniy

By Torulf Wiberg on 10 January, 2010 - 11:19 am

Evheniy,

Yes no problem, but please bear in mind that I have a rather busy schedule and limited time available.

Regards

/T

-------------------------------------------------------
Torulf Wiberg Tel. +46 (0)40 59 50 50
Deterministic Control AB Fax +46 (0)703 83 08 08
Derbyvägen 6E Dir. +46 (0)40 59 50 56
SE-212 35 Malmö
SWEDEN