Comment on proposed benchmark for testing PLCs by June 30, 2006

By Control Engineering Staff February 23, 2006

This PLC is fast. That PLC is faster. This other model is the world’s fastest. Are you comparing apples to oranges to rutabagas? Probably. That’s why you need to comment on “PLCopen TC3 TF Benchmarking,” if you haven’t already. The framework for fair comparisons was recently released for comments and is available for feedback until June 30, 2006. (PLCopen is a vendor- and product-independent worldwide association for resolving topics related to control programming to support the use of related international standards.)

PLCopen Task Force seeks comment from “a broader community about its usability for their environments before developing the applicable test software.” Published version is 0.4, and it is combined with a feedback form. PLCopen explains the need: “A benchmark is a reproducible, portable test to measure the performance of a given system in comparison to other systems. For PLC systems there are no defined benchmarks. The only common measurement for PLC performance is the execution speed of 1,000 Boolean operations. This number doesn’t provide a good benchmark, because one cannot derive the performance of the PLC in a typical application from it; consequently it’s not comparable between systems due to the lack of definition of the test conditions.”

Using a benchmark provides the ability to: 1) estimate the performance of the PLC in your own application; and 2) compare performance of the PLC with other PLCs and find the specific strength and weakness of a given system, the organization explains. The paper defines two sets of benchmarks, says PLCopen. The first set of benchmarks defines five types of applications typical for PLC use. Most applications belong either to one of these types or a mixture thereof. Second set of benchmarks measures each language feature of the IEC 61131-3 to exclude effects of other features as much as possible.

Find the free document with a feedback form at the PLCopen website.Look under “What’s New” to see “PLCopen TC3 – TF Benchmarking.”

—Mark T. Hoske, editor-in-chief, Control Engineering,