Is the SLC getting old?

We had an interesting discussion yesterday, about whether the SLC controller should be chosen for a project requiring a ten year service life. One of our engineers suggested that the SLC might be "silver series" soon, affecting its availability. I doubt the SLC is ready to go in the can, though, because it still has a very specific market that the Logix platforms really aren't right for. A Logix can do anything the SLC does, but it would be overkill in many cases.

What do you guys think? Is the SLC on its way out? When?
What about the PLC5? I still see those around. How many are new installations?

AK

I discussed this with our distributor yesterday. There is a huge installed base out there, and the SLC will be supported for many, many years to come. New software enhancements and hardware enhancements will dry up, but the SLC will be a viable platform for a long time. I suspect third party development will also continue for a long time as well.

I agree with Tom that the SLC family will be around for quite a while yet. As Tom said, with the current installed base Rockwell is much better off supplying replacements than making the platform obsolete, which might make someone choose another brand.

The PLC5 is a bit different. I believe you will be able to get new PL5's for quite some time yet. However, the prices are absolutely ridiculous compared to anything else in the Rockwell stable, at least from my distributor. This is Rockwell's way of steering the direction of technology without completely shafting legacy customers.

However, I would also seriously consider the CompactLogix platform. Our distributor has that platform priced to beat the SLC platform. The downfall of CompactLogix is the lack of specialty modules. But that will change with time. As long as a change to CompactLogix doesn't cause serious maintenance repercussions I would go CompactLogix.

Keith

kamenges said:

However, I would also seriously consider the CompactLogix platform. Our distributor has that platform priced to beat the SLC platform. The downfall of CompactLogix is the lack of specialty modules. But that will change with time. As long as a change to CompactLogix doesn't cause serious maintenance repercussions I would go CompactLogix.

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The CompactLogix uses the RSLogix5000 programming software, so I assume it functions like a ControlLogix. That would make it vastly different from a SLC, even if it is priced similarly. Learning RSLogix5000, for me, was a bit like learning to walk again. I imagine your mom-n-pop shop would rather stick with the SLC (I sense an ad campaign coming on) than try to convert code to Logix.

AK

Rockwell has said that "the SLC500 is nearing the end of its cycle". The same was said of the PLC5. Both will continue to be produced, but development of new features is pretty unlikely. Software revisions will be mostly of the "bug fix" variety.

If the PLC5 is any indication, I would expect prices to creep up on SLC hardware to discourage new installations. It's part manufacturing costs and part marketing (the manufacturing part is probably not as dramatic as it was for PLC5s which are quite complicated to produce). It still makes sense to put in new SLC500 systems for a customer that is familiar with them. I doubt it would be my first choice for a customer that does not already have an installed base of SLC500.

Everyone likes what they are familiar with. In the AB world most of my past experience was with PLC5s, most of my current experience is with ControlLogix. I've done SLC500s and Micrologix as well, I never came to accept their particular quirks as "normal" to me. I tend to think of them as PLC5s with some differences. I understand and acknowledge that people with more experience with SLC500s may have the opposite opinion.

Bottom line... If you use SLC500s exclusively now you may not switch this year or next, but it's probably time to at least get familiar with the alternatives.

One thing affecting all the PLC manufacturers is the availability of chips. Especially processors.

Rick Densing said:

One thing affecting all the PLC manufacturers is the availability of chips. Especially processors.

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Good point, Rick. Vacuum tubes are getting harder to find.

Our local rep, probably different from yours Tom and Ak,(we recently switched AB reps) were in a few weeks ago. I also brought up this question. They were pretty much along the same line that the SLC line will be around for many many more years.....though not much more in development.


Greg

GregPLC said:

Our local rep, probably different from yours Tom and Ak

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What? You're not going though Holt/Revere now?

No, we switched....Holt had dropped the ball with us too many times...Ever since the purchase by Revere, and the cut of the staff things just haven't been the same with Holt.

Greg

I dumped Holt a long time ago. I had problems with them back then. (8 or so years ago)

I work with Nelson now. I have worked with the same support engineers since then. Holt has turned over a couple times.

Now with the purchase by Revere, I would prefer to buy from a wisconsin owned company.

You're right on the money Rick. We went to Nelson....It was starting to become a training session with each inside sales person at Holt, every time I called to order something. They loused up several orders...purely their fault....they used to be so good. As I said, we went to Nelson and they are great, the experience really shows.

Greg

Vacuum tubes are getting harder to find???

Got plenty of 'em in this antique computer. Rebooting takes forever, they heat up one tube at a time!

If they would repackage the modules in some nice rounded profiles I'm not sure the instructions set nor the com. ability of these PLC would be a give away that they are that old.

SLC can still measure up to any others.

just a note

I saw the post concerning vacuum tubes, and just a tidbit of fun information. Being a guitarist, I'm particular about sound, and most guitarists will choose an all tube amp for pure sound over any solid state amp. For this reason, I know several places you can get a huge variety of vacuum tubes. If anyone needs some for any reason, let me know.

Russ