In this article we will highlight how to assign PID controller function block in with mode; in particularly Auto or manual. This applies to all Yokogawa STARDOM product line; such as FCJ, FCN, FCN-RTU. This might be a no brainer to some but for a beginners, a good reference.

Nevertheless, Yokogawa Logic Designer had a build in Global Variable called GM_MODE_MAN and GM_MODE_AUT for manual and automatic modes for PID controllers. That is what we should be using to assign the modes. There other modes such as GM_MODE_IMAN, GM_MODE_OS, etc, but they are not part of this discussion and will be covered in the next article.

You have to define the GM_MODE_* variable as shown below.

Xybernetics Yokogawa STARDOM - PID Mode Assignment

The mode are assigned to the PRM variable using the MOVE function block. The screenshot below outline how it is done.

Xybernetics Yokogawa STARDOM - PID Mode Assignment

Just to close the “loop”, below is a screenshot of how the PRM variable is used in a NPAS_PID function block.

Xybernetics Yokogawa STARDOM - PID Mode Assignment
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I am a software developer in Calgary, Alberta, Canada with passion in getting my fingers in any new technology. I started software development when I was 10 years old and have never looked back. Now with well over 35 years of software development, I wanted to share some of these key knowledge with the people of the world in the wide web.