Hi,

I am trying to figure out a reasonable benchmarking procedure for PLCs, so that I can have a couple of tests to run and compare the results among many different controllers.

Has anyone done any similar job already? Any tips for building this benchmark?

Thanks,

André

 

No, we haven't benchmarked PLCs --and for good reason.

It's like evaluating computer performance based on how fast the clock runs. You may get an answer, but it will be very nearly useless.

Your approach reminds me of the late Douglas Adams Hitchiker's Guide to the Galaxy books. The answer is 42. Now, what was the question?

Jake Brodsky
[email protected]

 

Sounds simple doesn't it? You could do this for your particular application. It would require
great care to make it meaningful as even ladder logic is not really portable. And how you implement can make large differences between
PLC's. It would be a noble effort and this information is something that would be of great value and obtainable no other way. Since PLC's
make the claim of being deterministic, you should be able to calculate the results for a given setup. It would be most instructive to compare
this as well.

Regards

cww

 

My suggestion would be to compile a list of features you need, and compare what is offered by various competitors. I would suggest looking over the specs first, as this will give you some ideas of what sorts of features you should consider. The type and usefullness of the I/O (including intelligent modules) is at least as important as the CPU features.
Once you have narrowed the field a bit, go over the instruction sets of each PLC to see how well they support features you need. A larger
instruction set isn't necessarily a better one, but have a look to see how easily it supports the common functions you need.
Remember to include things like availability in your area, support, documentation, training, software, and of course, price. Bench testing PLCs doesn't sound like a particularly promising approach to compare them unless you have a very specific feature in mind you want to test for a special purpose.

**********************
Michael Griffin
London, Ont. Canada
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Hi

I have been with AB for 4 years as a Sr. Automation Engr. for Tech Support and now im working here in Yokogawa

I do agree with you of looking with the Hardware specifications to see which could be the best PLC

to add to that its not just on the Hardware but on how to easily learn the system

one way is to get a particular system and measure how much time did it takes for you to develop a same Sequence of controls using different PLC brand and its programming software in that way Im sure that the most User Friendly Development software will be the best system to get. Of course add this to the Hardware Best Specifications !


anyway if you have additonal questions you can email me at:

[email protected]

Eduardo Manuel C. Cipriano
Sr. Systems Engr.
Yokogawa Phils. Inc.