Retained Data Table

[sgull]

Hi All,
I have a Data Table with fixed values that by reading a row and a column I can load a certain value into a program. I have set the Data Table to be retained and when I power down and back up all values are still there.

- What happens when the PLC battery dies? Are values in the Data Table still retained?
- There is the option to save the Data Table to SD card. Is it possible to load a Data Table, complete with values, from an SD card into the PLC on power up?

Regards,
Denis

[Saragani]

* Yes the battery keeps the values intact.

* There is an element "Load SDI from file", so you can load a table on the initial cycle (Note that loading the table would take many cycles, since it requires accessing the SD and reading a file. Once the load was completed, the status if the element would change to either 0 which is success, or a negative number which represents an error).

[sgull]

Thanks Saragani

When the battery fails I will lose the Data Table.

I have the Data Table is on the SD card but I still would not be able to load it because the element ^Load DT from file" also needs retained values.

I think with Visilogic you could clone a program to the SD card.

This allowed you to take the program with all set points etc. and copy them from one PLC to the next.

Is this available on Unilogic?

Regards

Denis

 

[Saragani]

I think that the Data table will lose the data when then PLC is turned off.

I think that replacing the battery while the PLC is still turned on should work (I see no reason why it should fail).

Load DTI file file accepts:

* A data table

* A file name (stored on SD)

* Start row

* Num of rows

* Status

 

 

The retained values can be stored to a file, and loaded when you need them.

 

In UniLogic you cannot clone or load a cloned project Via ladder, but from the UniApps.

System --> Upgrades --> User App Upgrade --> Import Application / Export Application

Memory --> Data Management --> Retained Tags Manage --> Import Retained Tags / Export Retained Tags

 

 

[sgull]

Thank You.

That should work.

When all settings are complete I can copy the program and retained tags to DOK.

On Battery fail the operator can load the project from DOK and then copy the retained tags back into the program.

When I tested this, it copied the program and the Data Table along with the table retained values from the PLC to DOK and back.

The other retained values were returned with the "import Retained Tags" command.

Thanks for all your help.

 

[Flex727]

Just to be clear, in order to lose data, both the battery must be dead AND the 24v power must be disconnected from the PLC. EITHER the battery or the 24v power supply will maintain all data. You can replace the battery with power connected without losing data.

[sgull]

Thanks Flex.

Yes, I am aware of this but most places will never check a display until something goes wrong,

With the Vision range I used to clone a program once I had a machine set up and all settings entered.

This clone contained the program and settings.

This program could be left with the customer on an SD card,

If the battery or PLC ever failed, the program wold be uploaded to the new PLC along with all settings.

I was not aware with UNISTREAM this had to be done with two files.

Regards

Denis

 

 

[Ausman]

15 hours ago, sgull said:

With the Vision range I used to clone a program once I had a machine set up and all settings entered.

This clone contained the program and settings.

Hi Denis, although a bit off topic, I have always been under the impression that Vision's clone works from the file on the PC.  Are you saying that it incorporates all "adjustable" elements ("all settings") by consulting with the PLC during the process?  My clones don't do this, but if it is possible I'd like to know about it given that the Vision forum often answers questions about how to easily duplicate everything.  If there is a simpler way than what is currently advised this would be good to know.

cheers, Aus

[Saragani]

You can clone directly from the PLC itself in a Vision PLC.

[Flex727]

7 hours ago, Saragani said:

You can clone directly from the PLC itself in a Vision PLC.

If you have a Set SD Password FB in the program.

[sgull]

Hi Aus

Saragani and Flex got there before me.

I find this really handy if the customer wants a copy of the program as it contains all settings as well.

Regards

Denis

 

[Ausman]

Ok, there may be a bit of misunderstanding here.  I am talking about doing it remotely.  I'm assuming that everyone here is talking about doing it using a card.  Hmmm.  Just realised that you could likely do this remotely, then read the card file remotely as well.

So c'mon gang, if this is the case, why didn't anyone pipe up during recent asks about "how to get all info out of the plc into a new one?'

But also, and I know I'm being stupid this morning, how do you do it if you don't have a unit with a card?

cheers, Aus

[Flex727]

2 hours ago, Ausman said:

why didn't anyone pipe up during recent asks about "how to get all info out of the plc into a new one?

Because it can't be done without the Set SD Password FB pre-existing in the program.