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](http://www.xybernetics.com/techtalk/YokogawaSTARDOM-PIDModeInPRM/images/SS01.png)
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](http://www.xybernetics.com/techtalk/YokogawaSTARDOM-PIDModeInPRM/images/SS02.png)
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](http://www.xybernetics.com/techtalk/YokogawaSTARDOM-PIDModeInPRM/images/SS03.png)