Cheap Automation Direct PLC's or Expensive AB?

For a small application, what PLC type is best? I was seriously considering buying an allen bradley 5/03. But I have just gone over some previous postings from fellow PLC enthusiasts, and this made me think I was going overboard with the expensive 5/03:

hate to muddy the waters, but have you considered an Automation Direct DL06? The PLC cost is $200-$250, software and cables are less than $200... All told you can get what you need, brand new, for less than $500 and still have plenty of room to expand in the future.

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This is very reasonable, and would probably be best for controlling a small feed mill system. It has a large 120/240 volt 7.5 amp motor, a silo unloader, and a few auger motors.

Because I only know how to program using RSLOGIX, I am not confident of trying a different PLC company.

The question: If Im pretty good at RSLOGIX programming, will the jump to a DLO6 PLC require alot of work to learn the programming?

I have ordered the AUTOMATIONDIRECT cd/catalogue, and will look into the type of programming involved. I only know ladder logic, and hope these small microcontroller PLC's also use ladder logic software. If anyone could tell me anything about programming a DLO6 that would be great.

I've used several packages (although not AD) and except for Siemens S7-300 series they've all been similar enough that the transition has not been too difficult. See if you can find any example AD logic or programming documentation, if it makes sense to you, then you'll do fine.

If you know basic ladder logic you should do just fine with the AD 205/05/06 series of products. There are a few differences, but as I've never done more than look at RSLOGIX code I'm not the best to describe them. You can download the user manual for the 06 and look through it to see some basic code examples here.

I just got done doing "quickie" 1/2 day training in DirectLogic and 205 PLCs for some operators in California that have only worked on Allen Bradley PLCs before. They picked it up very quickly, had no problems, and seemed impressed with the simplicity.

AutomationDirect.com isn't a cheap PLC, it is an inexpensive one. The quality and support are as good as any and better than most. Obviously you have to give up something, and you won't find compute or higher level math functions in the AutomationDirect products. There isn't quite the variety of I/O cards available either, and you don't have some of the options in I/O configuration. For your application, I doubt that this will matter much.

I think the PLC programming differences are not a big deal from what I have seen on the website.

so far i have went over the DLO6 PLC information available on the automation direct website. I like the clean and fast loading website, unlike the AB website that, in my opinion has a very confusing system of navigating. I also noticed the AB website makes it difficult to find the price, basically you have to put it in your online "shopping cart" before you can see the price of, for example, a 120VAC imput card.

On the other hand, from my first visit to Direct Automation webpage, I found is very easy to navigate/price compare/and easy to understand specification downloads.

Let me know your opinion about Automation Direct microcontroller PLC's. Are they generally cheaper than AB microcontrollers?

smfula said:

Let me know your opinion about Automation Direct microcontroller PLC's. Are they generally cheaper than AB microcontrollers?

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AD has a limited instruction set, compared to AB. If you can live without the compute instruction, ASCII functions, and trig functions AD is the way to go.

Assuming your local distributor is giving you fair pricing, Micrologix versus DL06 is a close race.

The DL-205 is the closest thing to the SLC controller. The pricing on IO modules may be close. The price difference on CPUs and add-on modules is where you start to notice a difference.

Look at your project requirements, and determine if the AD PLC has the features you need. If it does, go for it!

AK

I've used alot of differnet PLCs and I think AD is very simple.

It took me less than an hour to make the switch. The only thing I couldn't find was the edit mode. It drive me nuts for about 5 minutes until I asked my buddy. That was in the old version of the software. Now they have a big edit mode button that you can't miss.

Cost was what made me try AD. The easy to use software was just a bonus. It's been about nine years now and I've had very few problems.

Give it a try and Good Luck!!!

If its a "small application", do you need the power of a 5/03? I would think one of the AB Micrologix will suffice quite nicely. They program with RSlogix and most of the 5/03 instructions exist in the Micrologix.

Thanks for your helpful advice guys.

So...I guess after reviewing the comments, I should look into AB microLogix and compare it to the Automation Direct DLO6 PLC.

If anyone has a comment about which one is better let me know. I will try to look at the AB website and get my own idea of which is the best PLC at a reasonable cost. I am reluctant to leave AB because I am familiar with the RSLOGIX. But the Autodirect PLC's look pretty easy to learn. Others here probably agree with that. The price is good too!

akreel-i won't be using the fancy instruction set and trig functions that you talked about. I am just an amatuer here, and my background is simple ladder logic....timers, counters, mov multiply add sub functions, time on/off delay....thats the kind of stuff i remember.

Let me know if the advanced/complex "instruction set" that you talked about is vital to a small PLC application. Right now...i think just the simple ladder logic using basic a basic instruction set will be enough. What do you think?

smfula said:

akreel-i won't be using the fancy instruction set and trig functions that you talked about. I am just an amatuer here, and my background is simple ladder logic....timers, counters, mov multiply add sub functions, time on/off delay....thats the kind of stuff i remember.

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All of that's in the AD instruction set. I say go for it.
It certainly doesn't hurt to learn something new.

I noticed you listed the MOV command, though. You'll be using the load (LD) and output (OUT) commands in AD. Be sure to use the correct output command, too. There's one for coils/binary and a different one for word data. At least, that's what I remember. My AD is unfortunately a little rusty... I haven't gotten around to interfacing that DL05 with my Playstation2, yet.

AK

akreel said:

I noticed you listed the MOV command, though. You'll be using the load (LD) and output (OUT) commands in AD. ..... My AD is unfortunately a little rusty...

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No offence Ak but your right on the "rusty" issue. AD certinly does have the MOV command. (Which I use all over the place). I think if you actually compair the DL06 instruction set to other AB models you'll find that there aint much missing, if anything at all. This mighty tike has a real time clock, indirect addressing, subs, MCRs, retenative memory, an optional LCD display, floating point, on and on..

smfula,

Your application seems well suited to the DL-06. As a matter of fact It'll be like riding a rocket to the corner store. You can get a total setup, (PLC cables, programming software, & manual), likely for less then the cost of the comparable AB product.

Go for it!

As new to AD PLC (I Install only few DL06)Its strong mashine in small body.Its certainly better then AB ML.
It took me few hours to get the idea of programming.decent price and good support.
I would not chose ML any how.
Bottom Line
Go for it.

elevmike said:

No offence Ak but your right on the "rusty" issue.

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No problem, Mike. It's just one more reason I need to dig out my DL05's and go to town.

smfula,

So WE have decided for you: Get the Automation Direct DL-06!! I have used it also, and had no problems learning the AD ladder logic. Plenty of AD manuals online.

For a Feed Mill with several 220 volt motor starters, I would probably go with a DL-06 model with 120 vac inputs and relay output module. You will not need one of the 24 vdc models, unless there are things you have not told us...

Do you have existing Start/Stop Pushbuttons? If not, AD also has nice graphic panel control stations that interface with the PLC's.

I to am an AutomationDirect enthusiast but, before everyone goes off saying this is the only way to go please consider:

The type of PLC equipment which is already in place.

The cost of maintaining different spares.

The learning curve time.

Others who may follow who may have to be familiar with more than one PLC structure.

Problems with these could outweigh the difference in initial cost very quickly.