Due to all the (still) missing basic functionality in V15 (TIA), I don't plan to start using it any sooner than I have to. So I'm planning to get the Step7 v5.6 BASIC and the Step7 V15 BASIC.
My understanding is that v5.6 will program 300, 400 and 1500 PLC's, and the V15 (TIA) is needed only for the 1200 PLC's. Step7 V15 Professional can program all PLC's, but offers nothing extra over the V15 BASIC if one plans to use v5.6 for the other PLC's anyway.
Correct?
Very not correct.
Step 7 V5.6 covers the older 300/400 processors, and their variants (WinAC, ET200S, etc). There is no BASIC version, there is "regular" or Professional. Pro is a bundle of a few packages together (Step 7, PLCSIM, SCL, Graph).
Step 7 V15 Basic covers the 1200s, and also includes WInCC Basic for the Basic line of HMIs.
Step 7 V15 Pro adds most of the other PLCs to this (1200/300/400/1500). Note that it does have a HW cutoff: I think it only includes HW that was current as of 2007 or newer. This means a lot of legacy equipment isn't supported. It also doesn't support things like 300T or 400H.
There is also a V15 Pro COMBO license that allows you to use (on the same computer) v5.6 and V15.
I wouldn't recommend using Portal for 300/400 projects. It works, most of the time, but the improvements in Portal are focused on the 1200/1500 CPUs. The way Portal handles data blocks is a bit different from how Simatic Manager does it, and that can cause a lot of confusion with 300s. Also, the project in the PLC may not be compatible between Portal and Simatic Manager: if you download with v5.6, Portal may not be able to upload and vice versa.
I'd strongly recommend you take a look at the 1500s if you are doing new equipment. The initial release had a lot of limitations, but it now has equivalent functionality for the vast majority of what the older stuff could do, plus a ton of new functions.
I'm curious what the "still missing basic functionality" is, from your perspective. There are things missing, but I wouldn't call much of it "basic". EDIT:Unless you mean Portal paired with 300/400s, in which case, yeah. I think Siemens is kicking themselves over including them in the first place.
