How old is the 1756-L7 series?

Looking at controller options but don't want to have to upgrade again anytime soon. We are looking at a 10+ year lifetime on the plant.

Can anyone tell me what year the Rockwell 1756-L7 controllers were released? How about the Modicon Quantums? Siemens S7?

Any plus / minuses regarding each?

Appreciate any assistance.

1756-L7 are the most recent series and have only been out a year or so.

Modicon Quantum is a "family" rather than a "series", and has been around for decades. I'm not familiar enough with Modicon stuff to tell you what the most recent series is.

Ditto with Siemens S7; S7 is a "family" not a "series".

As far as not wanting to upgrade and a 10 year + lifespan: I shouldn't worry too much. There are still many, many factories running on PLC's from the 1980's out there. Whether they should be or not is another question, but they're still running!

If it were me, I'd be heading down the road of the 1756-L7 series. But that's only because I personally like AB gear. The latest Siemens or Modicon would do just as well.

ASF said:

1756-L7 are the most recent series and have only been out a year or so.

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Um...no. 5 years or so since they were first announced. Granted the variants have come out over the years so the L71 might be only a year or so. I can't recall what order they were released...L72/73/74/75/71?. I started a project back in 2011 using an L73.

The L7 series is mature enough to have a track record but young enough that it will be around a long time. They have a trade-up program so upgrading processors is fairly easy and 10+ will be fine.

Huh. Yeah, I had a rep come in spruiking the "new L71" maybe 18 months ago, maybe the other L7's came out earlier? New technology always takes longer to make it down under as well

I think a 1756-L8 is on the way. I would check with your distributor on timing.

On the Siemens side, I think they typically promise a minimum of 10 years support and spare part availability from the day they announce that something will be mature or phased out. Theoretically, anything you buy now should be ok for 10+ years. Also, as ASF said, PLC's last for a long time. The CPU is probably the part of the PLC that will last the longest.

The S7 300 family (similar for the 400) has been around since the 90's, but the most recent models were released maybe 5 years ago, with Profinet onboard the CPU.

The newest family of PLC's is the 1500, which was introduced about 2-3 years ago. If you're planning to make the jump to Siemens, this is the platform I'd target. I'm a big fan of the symbolic programming (though you can still do address based if you really want), and the integrated display & HW diagnostics can simplify a lot of commissioning problems. The downside is the the programming software essentially requires a newish high end laptop to run smoothly, and there are a few functions from the 300 family that the 1500's don't support yet.

Just to chime in on the Modicon processors...

These are now a mature product and i would avoid building new using them at this stage. The newer unity models will be around for years but the racks and IO are very chunky. For most systems, one of the new M580 processors will do you just fine. The X80 IO has a much smaller footprint. Programmed in Unity, which in my opinion has one of the best FBD editors out there.

TimOB said:

I think a 1756-L8 is on the way. I would check with your distributor on timing.

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I'm not sure if they are going to be called L8 but I have heard the same thing.

I would not recommend 'brand new' AB hardware. It takes a bit for their tech support people to get trained up. I still have issues from time to time with their tech support and the 755 drives and those have been out for a while.

You should look at M340 or M580 instead of Quantum, unless you need more than 4000 discrete IO and 1000 analog IO in one processor. An equivalent Quantum rack costs double M340. Go for M580 if you are going to use remote IO over ethernet.

If your application lends itself more to ladder logic programming you might prefer the allen bradley, if your application lends itself more to FBD and structured text you will definitely find Unity is nicer than RSLogix5000 in those department.

RSLogix Ethernet remote IO and produced/consumed tags are pretty nice, I haven't used the equivalent in M580 land from Schneider.

At RsTech Ed in San Diego earlier this month they did a presentation on the new application code manager and one of the slides had a 1756-L85E listed in it.

People were asking about it but they were not saying much.

But with that being said I would not recommend cutting edge gear for a new project because like most here I have experience with being burned by that in the past.

If you have a new project now go with the L7 series. I have a plant full of them and they are solid processors.