Hi all,

I want to know How the PLC/IHM exchange data
the ethernet link is very fast, why tags are exchanging only with maximum 100ms ?
Can I put all my tag with 100ms without limits ?

Concerning "limits" :
I read lot of thing with "maximum powertag by project" and "maximum powertag by screen", but it is not the "tag"
Where is the difference ?

Last question, when I use the function library to convert UDT "PLC" to UDT "IHM"  (in order to use faceplate) when I watch to the tag-table, the data are in the UDT format and, really, it's better

So, if my tag are "arrange" properly in struct an udt in the PLC, why not in the IHM ?
Is there a way, when I don't use faceplate, to put the PLCtag_UDT in the IHMtag_UDT ?
And, of course, if I change something in the UDT_PLC, the IHM_UDT change too !
(the way to use datablock without "optimised" is not a solution)

Thanks !

sixthomas

Concerning "limits" :

I read lot of thing with "maximum powertag by project" and "maximum powertag by screen", but it is not the "tag"
Where is the difference ?

 Hello,

The power tag is the tag used in WinCC and whose value is obtained and updated through connection with PLC, the tag is the general tag that may be internal tag used within the WinCC (internally without connection with PLC) or external tag (counting as power tag)

Also you may see the post of    UMENCHO

• In the following thread:Thread
  

sixthomas

why tags are exchanging only with maximum 100ms ? 

 Hello,

I want to understand why you want to update tags refresh faster than 100ms.

Human eye / brain can analyse 10 to 12 separate images per second, so you won't see the difference.

If it is for logging, then I understand why.

Best regards,

Hugo

Creating Faceplates with WinCC Runtime Advanced and Comfort Panels

 Hugo, some applications may require a faster data refresh because if you need for example to make an indicator to rotate, wel you will need the fastest rate if you don't want to see the rotation "stepped"...

Rockwell HMIs can update data up to 0.01s

100 ms is the fastest data rate allowed by HMI protocol over ethernet. Of course profinet can run at 1 ms, but for HMI it's 100 ms (or slower :D)

HugoD

 

sixthomas

why tags are exchanging only with maximum 100ms ? 

 Hello,

I want to understand why you want to update tags refresh faster than 100ms.

Human eye / brain can analyse 10 to 12 separate images per second, so you won't see the difference.

If it is for logging, then I understand why.

Best regards,

Hugo

Hi

First of all, thanks for reply.

1 -> Power tags, I agree with the logical, but when I count the tag and when I go to IHM>Property>Information, I don't find the same number !
My question was :
1 tag bool configured is 1 powertag ?
5 tag bool configured is 1 powertag ? (in the same DB or not)
1 tag string configured is 7 power tag ? 1 ?
etc....
And If I use UDT_IHM, perhaps I "win" some powertag, perhpas not.

2 -> Why 100ms ? because sometime I find the IHM is "latencing"
Maybe the IHM is really latence
Maybe 100ms is too long
Maybe I configured too many powertags
Maybe I configured too many powertags on one screen
I don't know...

Before TIA, I used a single DATABLOCK to put all the tag need by IHM, that was simple and "arrange"
Now, I use optimized datablock, and the "exchange table" is made by the TIA between PLC and IHM.

Typically, when I watch to the IHM tag, it use tags from everywhere in my plc datablocks
I know there is no "better program" but what do you think about that ?
Do you use a datablock dedicated to IHM-tag ? ot it doesn't matter ?

Davinator

 Hugo, some applications may require a faster data refresh because if you need for example to make an indicator to rotate, wel you will need the fastest rate if you don't want to see the rotation "stepped"...

Rockwell HMIs can update data up to 0.01s

100 ms is the fastest data rate allowed by HMI protocol over ethernet. Of course profinet can run at 1 ms, but for HMI it's 100 ms (or slower :D)

 

 Davinator,

I am currently working on a automated bridge crane application.

In one of the step, the crane move down during 5 secondes and I show the crane going down in the runtime.

I assure you that with the 100ms refresh time, you can't see any "stepped" in the movement of the crane.

It is totally fluid.

Maybe the "stepped" animation is because some application have too many objects in the screen.

There is a limitation in the number of simple and complex objects per screen.

I don't know Rockwell product very well, but your eye won't see the difference between 10ms and 100ms.

Best regards,

Hugo

Hello sixthomas,

about your question 1:

Each PLC tag which you access in the HMI is one powertag.

1 tag bool = 1 powertag
5 tag bool = 5 powertags
1 tag byte = 1 powertag
2 tag word = 2 powertags
1 tag dword = 1 powertag
...

(So everything that has its own name is a powertag.)

HMI tags (that exist in the HMI only) don't count as powertags.

After compiling the HMI you can look at the "Compile" information. You need to have the blue ( i ) symbol visible.

There is a line "Number of tags: X" and a line "Number of PowerTags used: Y".
(X = Y + number of HMI tags)

About your question with the struct:

If you use the DB not optimized and use absolute access you can use an HMI UDT to mirror the struct in the PLC.

You'd select the HMI UDT as the datatype of a tag and connect it for example to
"DB[Number].DBX0.0".

The uncomfortable thing here is that you have to insert the offset of each tag in the HMI UDT editor and if anything changes in the struct of the PLC you have to correct it in the HMI UDT struct, too.

But other than that you can access every part of the HMI UDT separately in the screen. Would look like "HMIUDTName.NameOfTagInHMIUDT".

So it has it's pros and cons and you have to decide weather it's fitting for your usecase or not.

H.J.

Hello sixthomas,

about your question 1:

Each PLC tag which you access in the HMI is one powertag.

1 tag bool = 1 powertag
5 tag bool = 5 powertags
1 tag byte = 1 powertag
2 tag word = 2 powertags
1 tag dword = 1 powertag
...

(So everything that has its own name is a powertag.)

 Is this "tag counting" the same case with wincc 7.4 scada.