preserving DB content

[panic mode 246]

hi everyone, i am about to make change to a program with some really big DB that contains many presets. I have to add few more values to the end of that block but I would like to preserve all existing values. is there a working / recommended method of doing this? I don't want to retype hundreds of values. regards, panic

[Rod_Hackney 2]

You could open the DB block you wish to make changes to and do a Save As from the menu and give it a DB block number not shown in your system. This will create another DB block with the contents of the one you are going to edit. then you can close it and open up the original to edit it. If something goes wrong with the original you could always open the backup and save it with the originals name to restore the original settings.

[panic mode 246]

i already have backup but the point is that structure of the DB will change (few more registers added at the block end) and i don't know if the last saved values in DB will be preserved after DB structure is modified (length of the block increased). if this is not the case i need a way to dump those values back into DB after it's length has been changed.

[jrw 12]

Open your project offline Now do an open project online Arrange your windows so you see the offline project and online project( You should see the blocks folders of both projects) Copy the online datablock to the offline project- clink yes to over write now add your items to the bottom (that part is important) Now download just the data block

[panic mode 246]

thank you, i opened offline copy of the DB, clicked on "Open Offline/Online partner" icon, once online I clicked save and closed the window. this saves live values from DB in PLC into offline copy of the same DB. opened offline copy again (all values show up), changed to declaration view (unfortunately saved values are not shown in this view but they are there!), added few more registers at the end of the DB, preset the values (so one can see in the future what the default value should be), saved DB and then downloaded to PLC. worked like charm.

[JesperMP 2]

My wish: Thay there will be a button or function to upload ALL the DBs like the you did with one DB. The copying of online DBs to an offline project from the S7 Manager doesnt work consistently for me. Sometimes it works, sometimes I loose symbols and declarations. I cannot figure out what causes what. Edited 7 Mar 2008 by JesperMP

[panic mode 246]

it is very powerfull platform with (unfortunately) equally very inefficient development enviroment. it is particularilly crippled with everything that has to be done online (uploading, monitoring, referencing, debugging, editing etc.). when i started using Step7 i was outraged that one can only monitor one code block at a time (two on 400 series). now that've been using it for a while, i would be more than happy if i could monitor that one code block. no, i would be happy if it worked on one single network...