ControlLogix 5550 sales restrictions in lieue of 5555

  • Thread starter Anthony Kerstens
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Thread Starter

Anthony Kerstens

For all those interested, I recently received this notice from my AB supplier excerpted as follows:

Rockwell Automation will continue to manufacture the ControlLogix5550, however, we are already seeing a significant decrease in demand. As a
result, Rockwell is taking the following actions:

-A price increase for the 5550 and memory modules will go into effect in November 2001.
-Sales of 5550 processors and memory will be restricted starting in November 2001. Only customers who have existing installations of the 5550 will be allowed to purchase new units.

We will continue to build new 5550 processors for one year after the sales restriction begins. Repairs and support for 5550 units will continue after we stop building new units, on an as required basis.
Finally we are pleased to announce plans for a 5555 processor model at a lower memory and price point. The 1756-L55M12 processor will offer more
memory then the 1756-L1M1 at a comparable cost. This processor will be available in fall 2001.

Anthony Kerstens P.Eng.

Mike Johnson

Does everybody feel that way about the 5550 processor. I seem to like the 5550 processor. If I had a choice between AB PLC-5, AB SLC 500, and
ControlLogix, I would go with the ControlLogix. Do most people hate the ControlLogix? Are there all kinds of horror stories about the ControlLogix
( please no Flash updating or the strict revision one has to pay attension to when using the programming software, processor, Cnet modules, Enet modules, RSLinx, OPC optimization issue, etc. )? Are there people who just had such a nightmarish start-up that they are banning the use of ControlLogix processors?
What is going on?

Mike Johnson

steve godfrey

I really like them. I would not hesitate to use them again. I believe the pros heavily outweigh the cons.

Steve Godfrey
ControlLogix is worth it just for the communication tools. If anyone has had to walk down to the plant floor to connect to ControlNet or DeviceNet then they would certainly appreciate connecting to these networks remotely through an ethernet connection. Connect an ethernet module for peer to peer and another ethernet for HMI's. Have multiple ControlNet modules for huge amounts of remote I/O. Installing a PLC 5 now would be like installing a PLC2 in 1990, you will be replacing it soon.


Roy Speers AScT
Control Specialist
Molson Canada

Trevor Ousey


After doing a couple from scratch, one with M02 servo modules, the flexibility and performance are great. But with flexibility some people can make their programmes difficult, as I have found.

One item which is a bit lacking is the DHRIO, not having global DH+ status words and only available as 57.6k on DH+ (at the moment). Both these can be a bother when integrating into an existing PLC5
and SLC environment. These are small issues with a great platform.

Trevor Ousey.
I've had great success with ControlLogix, and we now use it as our stnndard platform. It's still relatively new and has a few growing pains, but nothing that comes close to outweighing its strong points.