I am new to PLC programming, and working on an existing system using an S7-1200 PLC and a SIMATIC KTP700 HMI. Within the HMI tag table, there are several tags whose address is in the format as follows: %DB'X'.DBW["DB'Y'_Some_Struct.Struct_Data"] where 'X' and 'Y' are the numbers of global data blocks, and _Some_Struct.Some_Data is specific information within that DB. An example would be something like %DB4.DBW["DB6_HMI_1_Struct_Calibration.Int_Channel_1"], mapped to the HMI tag Int_Calibration_Channel_1.

The square brackets and double quotes are part of the address as well. I am unsure what this means, but the PLC tag is <Multiplex tag>. I am using TIA Portal V13 SP2, if that makes a difference.

Can anyone tell me what this addressing format means? My best guess is that it's some kind of dynamic addressing, but I am brand new to this.

Thank you in advance!

Hello,

Yes, it is dynamic addressing

Have a look here: Address multiplexing

And some example: How does tag multiplexing work? (It's about WinCC flexible, but it is the same in TIA Portal)

Best regards,

Wizard