Only $200K ?!?
That's what?, 2-3 programmers' salaries for only one year? And at the end of that year, you will have a full-featured, well-documented, bug-free product that runs on Win95, '98, NT, Win2K, XP, ME(?), under any service pack, and on any hardware? That's so user-friendly that you won't need tech support (or can justify having the customer pay it's full fare)
What's the communication link? RS-232? Will a USB or PCMCIA card be able to handle it, too?
I think you'll be hard-presed to pull it off (depending on the size of that 61131 subset).
You can tell that RSLogix has many more man-years in it than that. And don't forget, Rockwell does give away RSLinx for free, at least enough to take the comm burden off of the RSLogix developement team. OK, maybe it's Rockwell's fault that they have so many comm protocols (DF-1, DH+, DH-485, ethernet).
And then, like you said, there's a sales&marketing effort, product enhancements, accounting overhead, etc.
I understand Ken for leaving the debate. It has been done before (but then, so has most topics here - but you never know when you'll get a fresh insight). And it started with the old "Why is AB so expensive", which I'm sure he must be tired of hearing (I know I am - even if it is true).
On the other hand, I do agree with you about the bug fixes. The same should hold true for when the upgrade "only" supports a new line (or revsion) of hardware. (Although I could forgive Rockwell if, say, they came out with a SLC 5/06 that had built-in Devicenet - it might require a major S/W upgrade to support that.)
What bothers me most about this thread, though, is that Stephen Loft who started it, is the perveyor of free software for his company's line of PLCs. I had remembered that there was such a company rep who posted on the old site, and tried (but failed) to find the topic, so I could provide the info to him. I didn't realize, until Ron Doran's post, that it was he who originally posted it.
I guess it was his intention to get us all riled up, "Throw the Bastards Out", "Free Software", and then come to our rescue. From the general consensus, it looks like he failed.
I also feel that he misrepresented himself here. What does that say about how he represents his company?
Or, to sum up the whole thing in one word:
<center>TANSTAAFL
There Ain't No Such Thing As A Free Lunch</center>