TIA Portal: "Retain" setting in Instance DBs

[kdcui]

This may seem like a basic question, but for some reason I have having real trouble deciphering the built in help content, as well as navigating the official Siemens forums.

I have a program I've inherited (v14 of TIA Portal). There is an FB and a corresponding Instance DB (it is only instantiated once, so far). When I open this one IDB, the "Retain" setting is set for several (but not all) parameters, however the entire column is greyed out and I am unable to set (or unset) this setting.

I'm can't for the life of me figure out how to change this. I need to add some parameters to the FB definition and want to ensure they are retained.

Thanks.

 

[mk42]

This may seem like a basic question, but for some reason I have having real trouble deciphering the built in help content, as well as navigating the official Siemens forums.

I have a program I've inherited (v14 of TIA Portal). There is an FB and a corresponding Instance DB (it is only instantiated once, so far). When I open this one IDB, the "Retain" setting is set for several (but not all) parameters, however the entire column is greyed out and I am unable to set (or unset) this setting.

I'm can't for the life of me figure out how to change this. I need to add some parameters to the FB definition and want to ensure they are retained.

Thanks.

I believe it is set in the FB interface. Each parameter can be set as Retain/Non-retain/Set in IDB.

 

[kdcui]

Thanks, that was it - I completely missed this.
Does modifying this change anything about the memory reserve available for retention?

I know with PLC Tags, it is more specific / restrictive in that you need to click the "Retain Memory" button and then specify the address size (starting from address 0), and then the Retain is automatically applied to all tags starting from 0 to [Max Address].

Adding new tags into my FB and setting them to Retain did not seem to change the "Currently available retain memory" shown in the "Retain memory" menu accessible from the PLC tags list (I have a feeling they are treated separately).

 

[mk42]

The field you mention won't update until the blocks are compiled. The Program Info display has the same requirement (with the additional requirement that it only updates when it is opened or actively refreshed via the toolbar button).