Direct Logic PLC's

[ADMIRALKEN]

Hi,
Does anyone have any experience with Direct Logic PLC's.
I just visited thier web site, and the pricing is very inviting. We currently use Allen-Bradley every where. However, we are open to new things. Can anyone relate Direct Logic's limitations and or advantages (besides price).

I'm most curious about the handling of analog I/O and PID loops.

thanks,
Ken Moore

 

[Macbeth]

We have used many PLC direct controllers on many low-end jobs from the 105 to 405. Along with many of their OIT's. We use to not recommend them for wide scale process plant solution only because of limitations in networking but now days with Ethernet they have made our approval list. I would recommend you stay with 205 or 405; the 105 and 305 do have limitations. The only problem I have seen with 205 is the connectors on the cards don't always make good contact and lead to the appetence of bad fuses. The PID's are not in ladder logic they reside separately, although you can access memory from logic. You are limited to the number of loops you can have max 16. There loops for me tune real easy.
The I/O addresses are pre defined such as each slot has a memory range that is consumed by it. But they can be changed (if only to keep everyone confused.) They are not the I:2/4 they look more like X246, and then you would have to know where X246 was. Unlike AB there is only one type of memory although the memory is divided in to groups there is still only one type of memory "V memory" so it is possible to over write sections of memory.
Also, if you are an old guy and miss your RPN HP 11C calculator this is the Directsoft software is for you. But if you are one of though new guys with you TI-86 this means when you add some thing it goes like this

A+B=C
LOAD value A into memory
ADD value B to memory
MOVE memory to Value C

Well that a quick skiny.
I would Highly recomend thier switches they have no draw backs.

 

[ctolbert]

Admiralken and Macbeth:

Keep an eye out for the new catalog in a month or two. Quite a few of the issues you have brought up are solved

I'm not in sales or bean counting....just an applications/support guy for ADC.

If you want to know more, call us at tech support...it's free (other than the phone call itself).

770-844-4200

Happy to answer all your questions,
Carl

http://www.automationdirect.com

 

[skills]

I was the electrical engineer at an aluminum plant about 5 years ago and we used Direct Logic for everything except DCS systems. I replaced 11 AB SLC500 and was impressed with everything they do. I am sure that that may have some weaknesses; but, I can't think of a better PLC system for the way we design systems. AB is too cludgy and clunky for my taste. I design embedded systems using microchip and atmel processers and Direct Logic serves a computer systems designer mentality well. I am sure that an Allen Bradley SLC-500 can be stretched to do everything that a low end Direct Logic can do; but, I have not seen many AB people willing to challenge Direct Logic systems on any real world issues. The DirectSoft programming system is, in my opinion, the best and most comprehensive software for plc development, period. After you compare 2 medium size and fairly ambitious systems, I have found AB to be 3 times the cost it they can be used at all.

 

[roscoralf]

While I will agree that AB is expensive, I do use AB for larger projects and cheerfully use AutomationDirect PLCs and products on smaller ones. I have used the pulse-output capability fromt the $99 controller (D0-05DD) in several machines to control servos, and they work fine. In my opinion, there is no better small PLC than the DL-05 series. I don't think the software is better than AB, however....its hard to beat having variables updated in realtime right there, without building a variable table (Siemens, too). Anyway, AutomationDirect PLCs have my own humble endorsement.

 

[kamenges]

I'll toss my hat in with everyone else so far. I have a hard time coming up with something I don't like about Automation Direct (supplied by Koyo) plcs. I find them easy to program. They always seem to work. I have yet to run into a plc dead out of the box. I have used only the 205 and 405 series and highly recommend them. While I have yet to use it, I like the option of using the WinPLC in the 205 format. A 100Mhz processor running Windows CE with Think & Do preloaded sounds pretty sweet. One of these days...
The programming software is IMHO very easy to use and understand. The stage programming, which is kind of like a free-form function chart, is pretty nice once you get used to it.

Keith

 

[cfordyce]

I have standardized to Automation Direct PLCs in my Plant. DL06 for small apps and DL205 for greater io apps. I also have a SCADA Data Collection system implemented with DL405 modules/rack w/ Ethernet Base Controller to poll inputs and transfer to SCADA PC. Everything is working great.

Only place AD tech support is lacking is on Software Products they market... In my experience.

CAF

 

[jonesy29847]

We used AD processors in our plants for many years. They are a good processor and the I/O supported is fairly wide ranging. There are some pecularities, i've seen rungs that wouldn't work until you deleted them and reentered them (very rare), and maybe non-existent now. The software is cheap and you only need one package to support the entire line. We used them for assembly equipment. The one downside I had was support, there not like AB where you can call a distributor and get a manual, but if you have internet acess you can get any manual you want.

 

[dpatddc]

Online edits with the A-D processors are not bumpless. The processor is put into 'pause' while the changes are downloaded. If the machine isn't running at the time it's not a problem.