Since the HMI is simply a way to view the process, and we humans sometimes adjust the display attributes to help add information to the displayed values - sometimes we make mistakes that are very difficult to spot and cause us to look in the wrong places for answers. 

Sometimes we make works blink when a tag is in alarm or maybe to indicate something that is ON all the time, but maybe it runs a fan, so it flashes to simulate a fan spinning.

Check the HMI configuration / properties / attributes / alarms / triggers / scripts associated with that tag.  You can use the cross reference for the tag in the plc logic and find references to the tag that is not behaving like you want.

To me it sounds like the appearance flashing attribute is set in a way that it toggles when the device is ON by having two different colors associated with the same state of the tag - compared to say having it green when it is off and red when it is on.

alpr94

Duris_I  I really appreciate your help, I already tried using a counter, but the output is being activated normally, only one time, i mean is not flashing on programming. I already looked if the output is dependant of a clock by accident or something... But this is not what is happening... I'm really confused about this.