First off, a post to let you know we’re still here and alive. I’ve been buried on a startup for the last few weeks on nights. Inspiration is hard to find at 4:30 in the morning in a cave.
Anyway, a couple things I wanted to get out for our reader’s consumption.
First, if you aren’t reading Scott Whitlock’s blog over at ContactandCoil.com you are really missing out. He spans the gamut from hard core PLC’s to deep dives in .Net all the way over to garden scale trains. Anyway, he’s got a really neat idea (at least he wrote it up, don’t know if it’s his idea from scratch) on securing communications to your PLC networks. The basic idea is that instead of having machines from outside the network actively connect to the PLC’s, do it in reverse. Make the PLC actively connect to something on the other side of a one-way firewall. Sure there are some limitations to the approach but as a start it’s a really neat idea.
Second, got a lengthy comment from Roger Smith at Invensys on an older post that I thought had some great nuggets in it so I’m reposting it here for all to consume.
I stumbled across it while Googling for something else and saw my friend Howard’s name on a post. I just HAD to see what he was up to. After reading Andy’s post, and the responses, I thought I’d chime in on a couple of the topics discussed.
@Andy: I’m aware of the requirement for DCOM with A2 communications, but never would have thought to check to see if it had been disabled. Thanks for posting this, I’ll try to remember it for future (re)use. There’s a long line of people that would love to see DCOM replaced with something more firewall-friendly, like WCF, in a future release.
@Dan: I’m curious if you working with Operations 4.0 or newer? With that version Wonderware updated the MES Client API and middleware to support WCF, in part to get some relief from DCOM heartburn.
1) The new virtualization guide is included on the System Platform 2012 installation image, available on the WDN support website. Most of the content is built around discussion and examples of Hyper-V. This is likely because it’s a feature of Server 2008 R2 OS, rather than a 3rd party application, and perhaps due in part to Wonderware’s close relationship with Microsoft.
2) The requirement to disable UAC for Vista and newer OS was introduced with App Server 3.0 and InTouch 10.0 in 2007. It has been documented in the ReadMe.html file on the installation media for these products ever since. Perhaps because adoption of Vista and Server 2008 OS was slow, it seems that many users didn’t discover this requirement until working with Windows 7 and Server 2008 R2 more recently. Unfortunately, like the DCOM issue above, leaving UAC enabled results in a problem where the symptoms don’t necessarily point to the solution.
3) It was great to see you at OpsManage in Nashville!
That’s about all for now. Hopefully once the startups die down David and I will be back in the saddle again.