Small PLC eval

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Thread Starter

Curt Wuollet

Hi all

Since I suddenly have a lot more time, I've been finishing my eval of small PLCs for add ons and small stand alone projects. Many of you are familiar with the big name offerings in this arena, Micrologix, FX, etc. So, I've been looking at the newer offerings because like all electronics, PLCs should get better faster _and_ cheaper and you shouldn't have to pick any two of those.

I did a project with the GEFanuc Durus PLC. It's a joke, no math, no way to reference timer and counter internal regs,etc. It's really just a relay replacement with a little logic. The software was free and worth every penny. It was barely transliterated (not translated) from the Chinese and really seemed not done. Maybe rev 2 will be better.

The Click from Koyo aka Automation Direct, seems to be a killer product. Less expensive, but with a much wider range of instructions, even floating point math and decimal addressing. This software is also
free and the PLC itself starts at $69. It does need a power supply
which blunts that a bit, and it lacks the display and buttons on the
Durus, but the project I did on the Duras was much smaller and easier
to do with the Click instruction set. IO is very reasonable with DC points at less than $3. One notable missing part was analog, internal or add on. That seems curious as most of the newer offerings seem to throw in a couple inputs or at least an add on.

I don't have a Windows machine here at home, and I'm a little reluctant to buy a Click on unemployment, but it would surely be the one to buy under these circumstances, and if I get a few bucks ahead, I'll get a Click and do the hardware side. If anyone has a Windows license to contribute to the cause, I can round up a spare hdd for my laptop. I left the Click software on the laptop at my previous employer.


Regards

cww
 
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William Sturm

Curt,

Have you ever looked at the EZAutomation PLC's?  They have great features, the price is right, and they are even assembled in the USA.  I have never used one, but I would like to someday.

Bill Sturm

Abbeytronics LLC
 
So far as the GE Fanuc Durus is concerned, you can get virtually identical hardware from a number of companies. I think the other vendors call it a "programmable relay" rather than a "PLC". Most people program these type of things through the keypad rather than using the software. They are suitable for replacing a couple of relays, and that's about it.

As far as the Koyo "Click" is concerned, I modeled the current version of my MBLogic soft logic instruction set after the "Click". I only have IL and not ladder at this time, and the "Click" has ladder but not IL, so I just modeled the IL instruction names on the ones used in their older products (with some new IL syntax for instructions with no equivalent).

As a result of this, I've analysed every instruction in some detail. So far as I can see the instruction set is very complete. When they say it has "21 instructions", they mean it has 21 *kinds* of instructions (e.g they count "math" as 1 instruction). If you count the actual individual instructions, there are over 100. The word oriented instructions also do a lot of automatic data type conversion, so they can do things with one instruction that would take most other PLCs several instructions to accomplish. It may be inexpensive, but it's not low end in terms of what you can do with it. I can't see anything (so far as instructions are concerned) that it's missing. It doesn't have a PID instruction, but then it doesn't have any analogue hardware yet.

As far as analogue is concerned, they have an analogue address space (XD and YD addresses). They just don't have any analogue I/O cards yet (or other specialty cards). This is pretty normal for a new product though.

From looking at it, I suspect that this is the first model in a new product generation that will replace their older PLCs. They've dropped all trace of BCD and generally have just one way to do each task. Their older PLCs had excellent backwards compatibility, but they achieved that by just adding new instructions while keeping the old ones. With the "Click", they've started with a clean slate.

The word oriented instructions and word data table(s) are non-traditional, in that they operate more like a higher level language while still being ladder logic. That is, there are separate address ranges or tables (DS, DD, DF, TXT, etc.) for each data type instead of just stuffing everything into an array of untyped bytes (IEC style) or 16 bit words (Japanese style) and relying on the person writing the program to keep track of byte and word offsets. You can mix types in math equations (there is no accumulator) and the system will automatically do whatever type conversions are necessary. The same is true for compare and other instructions.

The addressing and memory to memory instructions were the reason that I chose this instruction set for a soft logic system. I had been working on a soft logic system using a more traditional style of PLC instruction set (their 205 series) but found this one to be much easier to implement. It also allows some very significant performance advantages for word and math operations. The way they did things more or less followed conclusions that I had come to independently about what sort of instruction set and addressing would suit a soft logic system. I implemented a few things differently than they did, extended the data table size, and made some other minor changes. I would much rather use something like this for a model though than base a system on something as convoluted and complex as for example a Siemens S7.

I can't comment on their hardware though, as I haven't bought one.
 
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Curt Wuollet

Right now a vendor would get a lot of points for having Linux programming software. The most expensive part of getting set up for PLC programming here at home is what MS wants for Windows XP. I don't know if there is a legal way to get a copy cheap even though there must be thousands of copies going in the trash every day. They seem to have achieved their Nirvana of one copy for every PC whether you use it or not. Even the notebook I want to put it on cost less than that.
I can buy a lot of wood pellets for $100 and it's hard to believe, but heat is more important at the moment. Tithing to Redmond is a non-starter. I'll have to see if Wine or similar will run the stuff. I'll check out EZAuto's web site.

Regards

cww
 
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Andrey Romanenko

Curt,

You may want to take a look at Fatek PLCs. They have analog and digital IOs and a PID instruction is in there, too. The programming software is free. You can use Modbus TCP to do data exchange.

Best Regards,
Andrey Romanenko
Ciengis - Advanced Process Control and Optimization
 
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Curt Wuollet

Yes, the more I look, the more impressed I am. They even have modbus as the default comms. And they list typical scan time as 1-2 mSec. This how vendors _should_ compete, it's all good for the user. Better, faster _and_ cheaper and a little more open. I even threw in a resume while I was on their site :^) Now, it they just had Linux programming software........

Regards
cww
 
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Ken Emmons Jr.

I think there is a time limited VMWare windows server image that MS puts out to promote their product. Use this with the free Vmware server or player application If all you want to do is try this software that might not be a bad start until you can find a legit copy of XP for cheap. Kind of a PITA I admit. Would windows 2000 work with the click software? You might find a used copy of that at bargain basement prices and use it with the free Vmware server.

KEJR
 
Curt-
I am a company representative for AVG/EZAutomation. I also teach a course in PLC's. Each student builds, programs and takes home one of EZ's integrated HMI/PLC mounted in a control cabinet with power supplies, cables, etc.

All can be purchased factory direct, except for the enclosure. My curriculum uses simulated sensors with programming to actuate relays and modulate simulated variable outputs.

All hardware and software for a complete panel costs me under $1,000.00

Contact me if you need any assistance.
[email protected]
Innovative Logical Controls, LLC
www.innovativelogicalcontrols.com
 
C
We are also coming up on Rummage Sale season. I can probably buy a malfunctioning machine with Windows on it cheaper than buying Windows. Problem is that the malfunction is almost always the Windows. It's one of those things that is always around with you don't need it. I had a notebook drive with WXP on it until just recently I got with my IBM T23 Laptop. I needed a drive for a Compaq Armada M700 I got free with battery issues. So I installed that drive and put Ubuntu Linux on it. It's just as well I suppose, the legality of that copy was not clear. Something will happen along if I wait long enough. It would be a lot easier to find if Vista hadn't bombed so badly.

Regards
cww
 
C
So far, I'm looking at $75, if I can solve the Windows problem. That's a Click PLC and free software plus tax. I may need to add $20 for a cable. For many people who would have Windows around, that means you can have a complete set up with a decent, main line product for less than $100.

And this is not crippleware like the RSL trial version or others. The point is that many more projects become feasible with this entry threshold. I can bid projects that are practical even in hard times. At the moment, it's the difference between being unemployed or being in the automation business :^)

Regards,
cww
 
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William Sturm

Curt,

We think somewhat alike.  I am underemployed, not unemployed.  I find work where I can.  If not, I'll take the time and maybe a few bucks to learn new skills.  I'm hoping to parlay this into a full time business.  We've got nothing to lose at this point.  I did get incorporated right away, you might consider that also, for liability reasons.  So far, I am designing a microcontroller based board, but I would like to quote small cost effective PLC based systems also.

Bill Sturm
Abbeytronics LLC
 
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Thomas McGarry

Curt,

With an AutomationDirect DL05, you can toggle an output using a single input, with just 4 instructions. Can this be done on a Click or with any of the other PLCs mentioned in this forum?

Tom
 
In reply to Thomas McGarry: The Click is more or less equivalent to the DL05/DL06 in terms of what the instructions can do. However, at present the DL05/06 have more hardware I/O expansion options. I would expect Koyo to eventually come out with more types of I/O module for the Click.

The Click's boolean instructions are almost one for one equivalent to those for the DL05/06. Counter and timer instructions are improved but still very conventional. The big changes are in the addressing (decimal instead of octal, no accumulator, "V" data table replaced with separate data tables for each data type), data types (no BCD numbers), and word instructions (more like using a higher level language).

Except for the I/O expansion options, if you can do something with a DL05/06, you can do it with a Click. I suspect that Koyo intends the Click to be the replacement for the DL05/06.
 
C
Do you mean like, on, off, on, for 3 pulses? They may have a flip flop function block for that. But, I don't have ready reference since I left my Click software at my previous job. I've got the help file around here someplace and I can look. Still no solution for getting Windows here.

Regards

cww
 
B
I didn't read back thru the entire thread, so I'm not sure what your objectives are, but have you looked at the Unitronics PLC? I haven't used one yet, but have one on order. You can get the software free, plus it has an integrated HMI. The instruction set is pretty complete and the base unit will take analog and high speed inputs, and it has PWM outputs. It will take RTDs and thermocouples directly, and the PID has auto-tune. One can add extra I/O, including a weigh scale module that takes load cell inputs. Modbus, Ethernet, CANbus, RS232/485 and other comm. options are available. Their low-end unit is under $180. The unit I ordered is under $500, with a graphics screen. One can troubleshoot with no PC, just the user interface. It has pretty amazing features for the price.

Perhaps someone who has actually used one can relate their experiences. After I play with the one I have on order, I will have some hands-on feedback. But if you want to review their offerings and see if it might fit your application or download the software, they are at www.unitronics.com.

Cheers-
Bruce A.
 
>In reply to Thomas McGarry:

Looking forward to CLICK analog modules, then can replace the DL05/06.

I would also like to see an ASCII read feature that is enabled all of the time and has an additional status bit to indicate when a char has arrived. The current instruction doesn't handle that very well IMHO.
Cheers
 
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