Strange A/D resolution: 1 count out of 6,000. How do they get that?

I'm looking at the specs of an Omron CPM1A-AD041 analog module and if I am interpreting the specs correctly (they are not in English) the resolution of the modules is 6,000 counts.

6,000 count resolution works out to be something like twelve and a half bits. What gives with that?

Or am I missing something obvious here?

A/D counters are usually built at 16 bit, then rounded down for accuracy.
At 15 or 16 bits, some counts may be missing. By rounding down to 12 or 13, they can give the spec of 'No Missing Codes'.

http://oeiwcsnts1.omron.com/pdfcatal.nsf/PDFLookupByUniqueID/946E50DB851773CF86256B1E00719F1B/$FILE/M11FrSTA08.pdf?OpenElement

Page 5
-2000 - +2000
-10 - +10

From what I can tell, it's hexadecimal which translates to 8192 decimal, which is 13 bit resolution.

I couldn't find a manual in english.
That's rough.

It figures, I had to go all the way to OZ to find an English specification. Sure enough, it is 6,000 counts.



I noticed that this seems to be a fairly common specification for Omron analog IO. It seems to be a strange number to me - but then again, it is the up side down side of the world.

Omron not that bad

I happen to work with Omron more so than any of the others, and there gear is pretty good, like anything, once you get to grips with it, at all makes sense.

The PLC you quoted is for one of the smaller 'brick' style PLC's, with the AD041 an expansion module. I have a couple of the larger processors that I look after, and am pretty sure that these have the larger resolution, 0-4095.

I have just started a project with the new CP1H, this model has 24/16 Digital, with 4AI & 2AO, the resolution of the analogues is 1-6000, or 1-12000, I agree though, it was different to what I expected, I am guessing that it is due to the smaller unit size.

If you are looking at Omron though, and only a small model, the CP1H range that has just been released ( here in NZ anyway ) is quite a useful little unit, supports Function Blocks, not like the other brands, but still enables the use of ST which can be quite useful. Also has a feature to display codes on the 7-segment display, which could be useful if no HMI present.

Am surprised about the lack of english manuals though, the local Omron website has them I think. I have them on CD anyway.

It figures, I had to go all the way to OZ to find an English specification. Sure enough, it is 6,000 counts.

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Not surprised at all. Have seen this with some other brands also. Oz is good by the way.

but then again, it is the up side down side of the world. Today 07:26 AM

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Behave, it is the BEST side of the world. Great for left handed people (that will probably go right over the top)!!!!!

Great wines particularly big reds in Oz - no watery stuff like from California and France. Some great whites too and also great whites from the "land of the great white cloud". Don't like their reds though. (That will also probably go right over the top).

Scott, I am glad I have a supporter here. Have yet to find software that comes even close to CX-Programmer V6.1. Love the configurability and the key strokes instead of drag and drop.

I am not sure that the Digital Library is available in other parts of the world away from the BEST side of the world. This extremely useful tool appears to be limited to Oz and the "land of the great white cloud". I know it was developed in Oz and I actually beta tested it (unofficially). It is really very good. I no longer carry any paper manuals as I do not need them.

BobB said:

Not surprised at all. Have seen this with some other brands also.

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That particualar model appears to be an Asian model number - so that why I had to go to the Asia/Pacific region.

Behave, it is the BEST side of the world. Great for left handed people (that will probably go right over the top)!!!!!

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Does that have anything to do with the direction your toilet water spins?


Thanks for the replies.

BobB said:

Great wines particularly big reds in Oz - no watery stuff like from California and France. Some great whites too and also great whites from the "land of the great white cloud". Don't like their reds though. (That will also probably go right over the top).

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How much is the wine out there i spend a fortune on ozzy and nz red.............

An example from the uk -
Wolf Blass Yellow Label 2003 Cabernet Sauvignon around £45 GBP for six bottles (unless on offer somewhere)

Dilema......... Would i save enough on red wine to move to oz

Mystery solved: It appears that these models are not UL approved - that's probably why I can't find any info on them on Omron's North American web site and why I had to trek all the way to OZ to find it.

I wonder if they are CE marked as I couldn't find info in the UK either. Does OZ use CE approvals? Does IEC prevail in OZ, or is it something else?

Pretty much IEC but CE, UL, C Tick etc are all called for and used as well as Lloyds etc. Nobody worries about these things unless a specification calls for them.

With respect to wine, I do not drink Wolf Blass as I consider it over priced and not up to scratch quite frankly.

As an indication I understand Jacobs Creek is very readily available over there. For the standard Jacobs Creek (cooking wine) we can buy it for about $7.00 AU and the reserve range, which is quite good, about $12.00 AU.

The range of reds here is awesome and I purchased some Shiraz from Jabiru winery recently - 2000 vintage. The winery is on Kangaroo Island just off the South Australian coastline. I did not even know there were wineries there. The shiraz is "huge" and will only get much better with time - it will not last that long. I tried to get some more but it was all gone. I paid a fair bit for it at $20.00 AU per bottle. Mostly I pay between $12 and $20 per bottle for really good reds.

I find most of the reds from Western Australia are too small for much but the French claim even these are too big. Man, they ought to try a really big one.

I do not know if you see Lindemans Pyrus over there but it is an absolutely premium red blend. Normally sells for about $55 per bottle here. There is so much wine around that I recently paid $25 per bottle for the 2000 vintage - it is wonderfull.

As I said, Oz is good.