Earlier this year I reviewed TwinCAT 3 and I admit that it was a less than stellar review. Up to now TwinCAT 3 has seemed like a beta all the way.

Well, I’m pleased to say that after using and deploying TwinCAT 3.1 for several weeks, it’s a significant improvement over its predecessor, and brings it into the realm of “release-quality” software. There are several improvements I’ll try to highlight.

64-bit! Finally! Yes, it’s so nice to get rid of the old 32-bit copy of Windows 7 and get back to the world of 64-bit computing.

The TwinSAFE safety editor is so much better. While the old one would take several minutes to verify my safety program before downloading it, and several minutes to even get online with the safety controller, this new version does it in seconds. It was so fast in comparison that I thought it didn’t work the first time. Thank goodness because that was a major shortcoming of the old version.

I’m pleased to report that Beckhoff has made changes to the source code file format to make them more friendly to source control applications (like Subversion or Mercurial). Doing a “diff” between 2 file versions now gives you a really good idea of what changed, rather than some obscure XML code. This is one of the first things I complained about and I didn’t expect it to get changed, so I’m really happy to see that. (Also remember that TwinCAT 2 files were completely unfriendly to Source Control; they were just a big binary blob!) Note that when you upgrade your TwinCAT 3.0 solution to TwinCAT 3.1, it has to do a conversion, and it’s one-way. Keep a backup of your old version just in case. In our case, the upgrade went well, except for references, but that was ok…

The old library manager in each PLC project has been replaced by a References folder, which you will be familiar with if you do any sort of .NET programming. You can now add and remove library references right in the solution tree, which is nice. That’s one thing that didn’t get upgraded automatically. I had to remove my old references to the TwinCAT 3.0 standard libraries and re-add them as TwinCAT 3.1 libraries. Not a big deal once I figured out what was causing the build error.

The scope viewer has been removed from the system tray icon menu and pulled into the Visual Studio interface. I think this is just part of their attempt to pull everything into one environment, which I applaud.

Unfortunately I still had one blue-screen-of-death when I tried to do an online change, but I couldn’t reproduce that problem. I’m using a commercial desktop computer, not an industrial PC for my testing, and Beckhoff says they won’t support the software if it isn’t installed on Beckhoff hardware. Let that be a warning to you: even though you pay significantly more for the software license in order to run it on non-Beckhoff hardware, they will not warranty software bugs in that case. That doesn’t mean you can’t get local support, but it does mean that if you have a legitimate bug report, they won’t help you unless it can be reproduced on Beckhoff hardware.

While upgrading, I also upgraded the operating system on the PC from Windows 7 32-bit to Windows 7 64-bit. That created a small problem because it caused the Beckhoff generated system ID to change, and the license is attached to the system ID. That means I have to go through generating a license file and applying the response file again. Hopefully there are no problems with duplicate licensing, as it is the same physical computer. I’m still waiting for a response though.

I did run into a couple gotchas during the upgrade. First, TwinCAT 3.1, for whatever reason, requires Intel’s Virtualization Technology Extentions (VTx) to be enabled in the BIOS, and mine weren’t. It turns out that I needed to flash the BIOS to even get that option. Secondly, we use Kaspersky Endpoint Security version 8 for our enterprise anti-virus solution. It turns out that both version 8 and version 6 prevent TwinCAT 3.1 from booting the PLC runtime into Run Mode on startup. Without Kaspersky installed it worked fine. I eventually tried Microsoft Security Essentials (the free Anti-virus solution from Microsoft) and that seems to work well. Some anti-virus is better than none, I figure.

The upgraded system has been in production for nearly 2 weeks, and seems to be working well (no problems that I can attribute directly to TwinCAT, at any rate).

In summary, if you’re looking to jump into TwinCAT 3, I know I said to wait in my last review, but I now think that TwinCAT 3.1 is a good solid base if you’re looking to get your feet wet.