It is hard to not sound unappreciative... but please try & include specific links to the most general of background pages on recommendations. Or terms to find same.
Google is not yet able to read minds as to my needs/intent. I waded through a dozen links on the S7-1200 trying to find one NOT...
Sounds interesting
Rant: They could learn from A-D about usability of web pages. I'm in a maze of twisty little web pages, all alike. XYZZY was no help at all.
I'm seeking the basic stuph; what you need to get started, etc. I find everything but.
[Can you guess the WX here turned hot and...
I've learned enough already that I should restate my requirements:
a) Small PLC, i.e. inexpensive.
b) Remoted I/O as well as ones at CPU, <10 I's & O's at each.
c) DC Powered [It's controlling a backup power system, so...]
d) No large one-time costs [i.e. programming sw license, etc]
e)...
I like Ethernet! I'm off to read up on it.
(While the DL-440 looks like it would work, it's ~10X the price of the ClickPLC and far more complex than I want or need.)
It's clear the AC measuring is a luxury best met other ways; I can use phase monitors such as the...
I must disagree; we do not know enough to say that it won't smoke on 50 Hz.
Is this a cell phone charger, or a lift truck's? 50 ma at 3 v; or 5000 amps at 48? Is it ferroresonant, or 500 khz switcher?
I'll go read up on the DL-405; I infer this is not a Click-PLC, however?
The RS-232 is easy. It's what I was told re: comms programming that bothered me.
Hmm, the -405 TFM makes mention of a DC-powered DL-440, a real plus. Lots of pictures of communications at the beginning. I find DirectNET...
Thanks but it looks like the ClickPLC is a dead end. There's no good way to have remote I/O. I can put a 2nd CPU at the other location, but the comms between them is convoluted, I'm told.
So I must reopen my PLC search.... Grrr.
(And one, much less 3, of the above would cost more than...
I concur that a suitable SSR on the AC would be a better approach.
You could make mountains out of molehills, and build a IGFET-based DC "relay", but why create trouble?
I need to choose and deploy a simple PLC. It will have about 10 digital inputs and 10 digital outputs, split between two specific locations. The main & remote locations will be connected by 100baseT and RS-232, carried by some fiber converters we're using.
It would be nice to also be able to...
A switcher would do better than a real transformer.
A 60hz transformer will likely overheat on 50 Hz; maybe slightly, maybe destructively.
Tell us more specifics on the charger.
I've not found a suitable remote propane tank level gauge. The propane tank industry seems to sell them with built-in cell phones, to call them; not very useful when you want a local readout....and there's no cellphone coverage.
I do find <http://www.rochestergauges.com/Pages/PDFs/R3D.pdf> &...
Can you get a metallurgist to look at the remains? I know nothing of the field, but am regularly amazed when I read NTSB reports on aviation/rail events. They can tell where where why and how a landing gear strut failed, or the turbine blade first cracked, etc.
So from what I've read, when you have a generator or other alternate power source, and transfer switch, each is a SDS, and that switch should switch the neutral as well. Neutral is grounded at the source.
But the case I'm looking at will have a utility xfmr w/wye secondary at the transfer...
jraef
Interesting approach; wonder which seminar it was you took? There seem to be as many S7 ones as there are competing PLC's.
I've starting in on finding a PLC to sequence/control a backup power system in a house -- about 10 inputs and 10 outputs. (The last time I even looked at the field...
After minor analysis, I decided it was the 120Vac powered version {the inputs led to half the primary of a stepdown xfmr; and the only AC options in TFM were 120 & 240.}, powered it up, and fed it some currents.
It works as represented and looks pretty, too. I can see why alehman's clients like...
BTW, the "MSP" acronym was the electrician's usage. I'd never heard it before, but when in Rome.....
If you want acronym confusion, I recommend a tour at NASA; the directory of acronyms used on the Shuttle is a big book; and while the book has a title, everyone uses the title's acronym.
