Thanks for your quick response!
Ok, that's clear. But which part is leading? If I have a DINT in my AB PLC, and I want to declare it in TS, I have to select underneath Tag Properties => Input / Output a DINT (as in the PLC). But what do I have to choose in the General tab as a Data Type? The INT (from 32 bits) or the LONG (from 64 bits)?