Umm...
Phil W,
It's always fun to watch the AB guys step up like this. Honestly, given that it was a simple suggestion to consider Uni's, a person might think your were offensensitive, or something.
But since you bring it up, I'm not advertising for Unitronics - I don't work for them. I once favored AB myself, but now I use Unitronics products to exclusion.
Why? Umm...
1. Battery? Good for seven years, backs up the ram and the RTC. Replacable? I don't know, I haven't needed to replace one yet. But the RTC is standard equipment on even the most basic M90 in the product line, and so are the logic funstion blocks that make it a breeze to use.
Speaking of software, why not cruise over to
www.unitronics.com and download it? Check it out. See what it can do. After all, it's FREE!
2. Eeprom? All unitronics products store their program in eeprom. The battery-backed ram is used only for process data.
By the way, did you know that ALL unitronics products store the COMPLETE PROGRAM in memory every time you download? That means if your computer croaks, you can upload and have a complete, annotated copy of the program, exactly as it went in. All titles, comments, everything.
Say...umm...is there an AB that will do that? Anywhere? And if so, for how much? Because the most basic M90 starting at <$300 american will.
3. Online editing? True, we don't do that either. But there is this spiffy little trick the Uni's have to work around it.
When you download to a Unitronics, if the changes are not extreme (like a completely different program from the one in it), the processor does not stop. The entire program is downloaded into memory, and at a point in between program scans, the Uni switches from the old copy to the new, seamlessly. It then erases the old copy from memory.
Do the Micrologix do that? Seems to my memory they don't. Cute trick tho, eh?
Finally, as regards your statement that I am "advertising", as said, I don't work for Unitronics. I find it interesting that you would try to exclude them from the debate though.
Say, you don't happen to work for Allen-Bradley, do you?
Umm...
TM