How to delete a block from online PLC?

Bofely

1. I have a offline DB with set start values.

2. Offline DB is downloaded.

3. Some set start values need to be changed, I make the changes in the offline DB.

4. "Initialize setpoints" (in DB block view) is the best way to overwrite the online values with the offline values, but somehow it's not available (greyed out). Another way is to delete the online block and download the offline block.

AutoGen_405229

I understand, but I have someadditional questions:

Do you want to make Step 4 in RUN mode of the PLC? Do you want to initialize all variables or just some (usually variables are set by the program)?

If you would delete the online block and then - later - download the offline block, wouldn't you get runtimeproblems while the DB is not there? Wouldn't the program still try to access the DB?

Bofely

AutoGen_405229

I understand, but I have someadditional questions:

Do you want to make Step 4 in RUN mode of the PLC? Do you want to initialize all variables or just some (usually variables are set by the program)?

If you would delete the online block and then - later - download the offline block, wouldn't you get runtimeproblems while the DB is not there? Wouldn't the program still try to access the DB?

I want to initialize just some. Initialize all variables is fine too. These variables are constants and will not be set by the program.

The PLC can be in stop for this action. If you do this in run then you can catch the error/problem with programming error OB (for access DB error). But for my situation the PLC can be in stop.

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The workaround that I use is to change the DB structure. E.g. adding a new element/variable, then the online DB can be overwritten with the offline DB. (Not a nice way to do, but I don't know any better.)

hdhosseini

There is an instruction here.See

Deleting blocks online

Procedure

To delete a block that exists online, follow these steps:

1. In the "Program blocks" folder in the project tree, right-click on the block that you wish to delete from the device.
2. Select the "Delete" command from the shortcut menu.

   The "Delete" dialog opens.

3. Select the "Delete from device" check box.
4. Click "Yes".

   The block will be deleted from the device online.

I did it for S7 300,Try for S7 1500 and update

 2022 S7-1515 and TIA V15.1 = I´m trying to do this. I select the "Delete" command and does not open any dialog, just the offline disappear and online remains grayed even doing this in online state and the status of PLC is not green anymore showing a warning about online-offline difference. The grayed block does not have delete option.  How can I desapear definitively a DB block that is not necesary any more?

MaggSan

 

hdhosseini

There is an instruction here.See

Deleting blocks online

Procedure

To delete a block that exists online, follow these steps:

1. In the "Program blocks" folder in the project tree, right-click on the block that you wish to delete from the device.
2. Select the "Delete" command from the shortcut menu.

   The "Delete" dialog opens.

3. Select the "Delete from device" check box.
4. Click "Yes".

   The block will be deleted from the device online.

I did it for S7 300,Try for S7 1500 and update

 2022 S7-1515 and TIA V15.1 = I´m trying to do this. I select the "Delete" command and does not open any dialog, just the offline disappear and online remains grayed even doing this in online state and the status of PLC is not green anymore showing a warning about online-offline difference. The grayed block does not have delete option.  How can I desapear definitively a DB block that is not necesary any more?

 When you delete a DB, then you need to download the software, to get the deleted DB off from the PLC. But when it's about DB's, TIA will ask for DB initializations of DB's when you do that, and if you proceed, all DB's will be set to start values.