History of PLCs

[Jim Dungar]

Jose,

How can the year of introduction of a product family provide you with any meaningful conclusion?

For example, some of the Modicon Quantum CPU history,
140CPU11302 - introduced in 1994 still available
140CPU21304 - introduced in 1994, no longer available
140CPU43412 - introduced about 1999, no longer available
140CPU43412A - introduced about 2000, currently available
140CPU65150 - introduced 2004

From this do you say the Quantum is old, obsolete, or brand new?

 

[msinclair]

You may have seen this site (and you have the data for the PLC5 already), but, you might find this interesting:

PLC5 History

To Jim's point though, I have a PLC-5 (ControlNet 1.25) that was introduced in 1995 that is now silver series. I also have a PLC-5 that debuted in 1990 that is fully supported (no silver series in sight!).

Marc

 

[Ken Roach]

SLC-500 original controllers were introduced in 1988.
SLC-500 "enhanced" controllers were introduced in 1993.
ControlLogix controllers were introduced in 1998.

I agree that any calculation of obsolescence is going to be less accurate than a compilation of manufacturer's information.

 

[José Serra]

I'm Agree

Thanks Ken.
Thanks Marc and Jim. I'm agree with both of you, the PLC5 family convince me about my error on trying to get any absolescense rating using the year of introduction. What do you think about include the year of each CPU?. May be useful. We still have the problem of how to use the availability factor. Perhaps availability of a direct replacement?. (CPU43412->CPU43412A). Or will be better use the status (Active, mature, discontinued). Any other ideas?

Of course we are also searching manufacturers's information (obsolescence stages and schedules).

 

[kamenges]

José-

It may get complicated but you are probably on the right track with your last post. A components current status, the availability of a direct or nearly direct replacement along with the replacements status is probably the closest you can get to projected obsolesence. No matter how you look at it, it's a little bit of a dice roll.

Keith

 

[José Serra]

I'm not losing hope

When I get all the information available about the diferent models (with manufacturer's information), an each individual Intalled PLC's, it will be possible disign a tool able to mix all factors and calculate a "obsolescense rating", wich can be more useful than manufacturer's information alone.