Control Engineering

David Chappell

What good is a wheel without an axle? Notification offer
December 4, 2007

The Make2Pack effort does not want to reinvent the wheel, it does want to provide a formalized and repeatable way to connect wheels together to improve the construction of the desired end result, a wagon say or even a car? How about manufacturing automation!

Today there is an automation standard that in my mind describes a lot of great wheels and how to make wheels for any need, the IEC 61499 standard on function blocks (see figure 1) is such a standard. Without these wheels the axle is of little use except to use to bash things into submission, which often is the approach used in automation today.

Make2Pack intends to leverage the 61499 standard as a core part of creating a formalized and standard way to connect the 61499 wheels to support multiple access and multiple control strategies that will have a consistent look and feel independent of vendor platforms.

Another significant goal is to provide a formalized way to separate the custom components in a way that will significantly improve end results.

The 61499 standard, like the S88 standard from ISA identifies the need to organize and coordinate control elements (Make2Pack is calling all of these items Control Components) to achieve the desired automation goal. 

Both of these great standards leave a bit too much to the imagination of the control engineer as how to do this and the results are very inconsistent from application to application.

Taking the 61499 concepts and building a shell around the function block that can be used to manage the coordination external connections in a formalized way is the approach being developed by the Make2Pack (M2P) effort.

Figure 2 represents a 61499 PID algorithm that has exposed some of the most useful inputs and outputs, as well as the Action Mode of Automatic and Manual.

[Please scroll down to see figures and remaining text.]

Figure 1: IEC 61499 Function Block

Figure 2: PID Example

Figure 3: Make2Pack Shell

In an upcoming Blog installment, I’ll share how Make2Pack envisions the full M2P shell shown in figure 3 will be used to apply 61499 function blocks in a formalized and consistent way to support multiple access and multiple control strategies.

[Among related Control Engineering articles on this topic, see: "IEC 61499 Function Blocks: A new way to design control systems?" Also, here's a short Wikipedia explanation on IEC 61499.]

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Posted by David Chappell on December 4, 2007 | Comments (1)