New Siemens PLCs S7-1200 and S7-1500, and TIA Portal software have already become quite mature products and they can be recommended for new projects now, but Step7 will be required for the support of old projects for a long time still. Recent release of the new version Step7 v5.6 (Step 7 Professional 2017) with Windows 10 support and my switching to Linux have induced a couple of issues I want to describe here.
I installed Step7 5.6 under Windows 10 and discovered that it lags significantly, with intensive load on HDD. It was especially obvious with demanding operations. Thus, for example, block comparison took 20 seconds vs 3 seconds in the old version. I tried Step7 v5.6 under Windows 7 — same problem. Then I discovered that the matter is not with the version of Step 7, but with the operation system — thus the old Step7 v5.5 lags under Windows 7 likewise.
I could have stayed under Windows XP, of course. The novelties are not essential for old projects. It is even more convenient to keep lean virtual machines with Windows XP. But it turned out that PC Adapter USB doesn’t work in virtual machines with Windows XP under Ubuntu host — it says “The device cannot start. (Code 10)” in Device Manager. It looks like there are solutions for that problem in the Web (install Extension Pack, add the current user to group “vboxusers”), but that didn’t work for me, and I didn’t want to spend too much time for further investigation. PC Adapter USB works fine in the same virtual machine under Windows 10 host. In Windows 7 under Ubuntu host, the error is the same if you put USB 2.0 in the settings of virtual machine, and the problem disappears if you put USB 3.0. Unfortunately, Windows XP does not support USB 3.0.
As a result, I have to keep a virtual machine with Step7 v.5.5 under Windows XP for current offline development, and another virtual machine with Step7 v.5.6 under Windows 7 or 10 for on-site work with PC Adapter USB. After making modifications in Step7 v5.6, you will still be able to work with that project in v5.5, if you don’t introduce principally new features (new generation of PLC etc), which is not likely on site.