Why does Contrologix seem to be unpopular?

Maybe it's just me but I get the impression in my industry (water and wastewater) that Contrologix is not widely accepted, or at least not nearly as accepted as SLC and PLC series gear. I'm curious as to why that is.

I design control and SCADA systems that use plcs but I don't program them. I leave that to experts like yourselves. Yup, I'm an engineer (civil) but please don't hold that against me. As a person who doesn't program plcs, I'm ignorant to the ease or difficulties of actually working with the various lines of plcs available. I try to use the best available technology for our clients but have to rely on information gained from integrators, vendors and sites like this (which is excellent, btw) to keep abreast of what's truly "best". Our industry, being somewhat conservative, tends to avoid using the leading edge just because it's possible . Tom Jenkins can probably attest to this. I'm just curious if the Contrologix avoidance is another symptom of that conservatism or if there's something else that people just don't like about it.

Thanks in advance.

tgreif

I have designed and programmed systems using PLC5, SLC, ControlLogix and others and from my experience the ControlLogix platform is by far the best choice in the AB line for ease of programming and the ability to implement different networks. There is no need to use block transfers, motion is implemented easily, the scan rate is very consistent and predictable and the use of user defined tags makes the logic very easy to be reused.

On the other hand, like most AB software packages, RSLogix 5000 has a lot of room for improvement. I have found that zoom in on the ladder does not work, ctrl-c and ctrl-v sometimes does not work for copy and paste and when writing a long program if one does not compact the program on a regular bases you take the chance of losing everything to your last save.

I think some of it is caused by cost.
At my facility we have 5 PLC-5's and around 30-40 SLC's. (Plus some old TI-565's, a DCS, etc..)
We have at least one spare of everything for the AB plcs. Plus we have several copies of RSLogix. Even though Control logix has been out a while, we still
routinely add additional SLC's, and expand our PLC-5's (5/80E's).

We keep saying the "Next" big project we will use ControlLogix, but when the time comes, and we add up the cost of new spares, new software, new training for our techs, we continue to use what we are already setup for.

I do not think we will change until, a REALLY big project comes along.


Ken

You posted this just to get me riled up, didn't you?

Currently, I am working on a project to replace a Bailey DCS system with ControlLogix at two large (300 MGD) treatment plants. I agree that this is not typical of wastewater facilities, but neither is having a DCS. I think there is a very hands-on mentality in some industries. How often have you seen equipment running in local-manual?

The SLC product line just couldn't do what we've got planned. ControlLogix is more network ready. We are installing this system to consolidate some of the control, while at the same time giving operators more access to information out in the plant. Even if nothing were to change from a control standpoint, ControlLogix cards are easier to come by (around here) than Bailey. Maintenance will be improved.

Hopefully, the final result will be the operator & dog scenario: The ideal control room has an operator and a dog. The operator is there to feed the dog. The dog is there to bite the operator if he touches anything.

AK

akreel said:

The SLC product line just couldn't do what we've got planned.

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I think that in most cases, it can. I have wanted to try CLx for quite a while and can't get any customers to bite. And it is true the SLC is perfectly adaquate for the job. Someday...

ControlLogix

I think if AB lives up to its own history they will eventually creep the prices on the SLC stuff up enough that everyone will be forced to use CLogix. The prices are already pretty close except for the processor and some of the specialty I/O cards.

Now for my 2 cents...

The PLC-5 and SLC-500 lines are so successful it's hard for companies to rationalize switching. There are training and cost issues to address when you move up to CLX. In addition to having to buy RSLogix5K you have to train people to think differently. I agree that the CLX is a better approach but the SLC has grown so nicely memory and I/O capacity wise that it fits lots of places just fine. In addition, RSLogix5K is not as mature as the 5 and 500 offerings. Furthermore, the similarities between the 5 and 500 are evident. CLX is a whole new bird.

Yup, most of my customers still want to use the old stuff.

(8{)} ( .)

Rick Densing said:

I think that in most cases, it can. I have wanted to try CLx for quite a while and can't get any customers to bite. And it is true the SLC is perfectly adaquate for the job. Someday...

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We'll be using a lot of the redundancy options: backup power supplies, SRM modules, etc. We'll also be using ControlNET and Ethernet, which aren't as easy to do on a SLC. We also liked the FBD and tag-naming conventions of the ControlLogix. I think the SLC could be used for this project and it would be 90% similar. It's the platform that I'm most comfortable with. But, we're using a boat-load of memory and ControlLogix was a much nicer fit.

On the down-side, we've got to work out a way to transfer blocks of data because polling one tag at a time is going to chew up bandwidth REAL fast. It's real easy to grab a group of 'N:xx' registers from a SLC. We'd like to avoid having to map ControlLogix tags to SLC/PLC registers, though.

AK

(8{)} ( .) said:

CLX is a whole new bird.

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It's like comparing apples to aircraft. Even things that seem the same are different.

AKReel

Are the plants on which you're using Contrologix the Jones Island and South plant there in Milwaukee. I know they designed an upgrade to the old Bailey system there. We went after the design for that one but lost it.

tgreif said:

AKReel

Are the plants on which you're using Contrologix the Jones Island and South plant there in Milwaukee. I know they designed an upgrade to the old Bailey system there. We went after the design for that one but lost it.

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If you read one of my posts in another thread, you'll see that you're right.

Everything old is new again!

Looking at the comments on the Clogix, it makes me think of how resistant I was when faced with the PLC-5/SLC500 stuff. I cut my teeth on the AB PLC-2 family and actually hardware before those. Using the addressing scheme and other things in that equipment became very comfortable after a while. Even using the old "T" type industrial terminals was not all that bad because there was nothing any better. Looking back on those days, I see now how lucky we all are to have the PC based programming software, addressing schemes that make better sense than octal ever did and all the nice things that Windows based stuff has brought. I would not give up a lap top and RSLogix to go back to a hand-held terminal for all the tea in you know where. So, like many have said, part of the problem is growing pains on the part of the users and yes, on the part of the people at AB who have to crank out all the things that go with this newer technology. Be assured that the growing pain phase will pass and once the CLogix has matured, there will be a faction that would not go back to a "Slick" if you threatened them with bodily harm. IMHO, in the words of the bard, this to shall pass!

we've got to work out a way to transfer blocks of data because polling one tag at a time is going to chew up bandwidth REAL fast

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Use UDT's and/or arrays to organise your data and RSLinx can retrieve them as blocks or they can be 'produced' as blocks.

there will be a faction that would not go back to a "Slick" if you threatened them with bodily harm

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Having progressed from 1774 to PLC2 to PLC3 to PLC5 to ControlLogix, I have never been a fan of the SLC - too many limitations for my taste, although I have been required to work with them on occasion.

I have so far avoided ControlLogix, so I can't tell you how they perform in our industry. However, I can tell you why I've avoided them so far.

1) High cost of entry. The hardware isn't bad, especially if you can substitute FlexLogix for ControlLogix. But RSLogix 5000 is expensive, and from what I've been told there is a significant learning curve to the transition from 500 to 5000

2) I have a huge "library" of past projects for the SLC that I can cut an paste into other SLC projects. I know that RSLogix 5000 has a function that is supposed to convert SLC logic, but even our distributor says it isn't 100%.

3) I have learned through bitter experience you don't want to be an early adapter for PLC products. BAsed on my past expereinces, you cantriple or quadruple that reluctance for Rockwell products. They just don't seem to hit the target the first time, or second, or third, or .......

4) There is no compelling reason to change that I can see, and even the Rockwell factory guys admit that unless you have a lot of I/O and huge logic requirements and tremendous data exchange there isn't a compelling reason to change platforms. I also feel that if I tie into ControlNet I am going to be locked in to another A-B proprietary protocol, which will limit future options.

If you send me a private message I can put you in touch with a very sharp wastewater specialist for Rockwell. He can help you decide if ControlLogix is appropriate for your individual project. I can also send you info on a paper I'm co-authoring for WEFTEC.

I have learned through bitter experience you don't want to be an early adapter for PLC products.

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No argument with that. However, taking up ControlLogix now cannot earn you the title of 'early adopter', as it is a good 5 years into its life cycle.

I also feel that if I tie into ControlNet I am going to be locked in to another A-B proprietary protocol, which will limit future options.

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Using ControlLogix carries no obligation to use ControlNet - I prefer ethernet. I would advise using ControlNet only if you really need its unique features.

As for the learning curve - it's most likely just going to get steeper the longer one waits.