Hi guys,

I'm encountering an issue here. I download this program from a LOGO controller at customer site. They want to change a couple things inside the logic. And I download the program, but however, i cannot add more logic gates in this program and they are all grayed out. I only can add Constants but no Basic/Special Functions can be added. Is there any settings wrong on this? 

I attached the screen shot of this problem in here. 

Any help would be appreciated!

Thanks,