Hello Guys,

I encounter a strange problem when programming PLC S7-1200. The system variables are behaving abnormally. I make a simple program using main OB containing 2 networks to see the status of variables "Always TRUE" and "Clock_0.5Hz". But both of them never ON.

I don't think there's another variable overwriting it, there isn't any FC or FB or networks in the program. How can I fix this?

Thank You All.

Hi,

in addition to that, here a screenshot from hwconfig (of course, the hw config must also be transfered to the cpu).

regards

sancruz

0_Einstein

Nearly every time a similar topic is posted, the attached image is helpful in fixing the problem.

Julham

Hello Guys,

I encounter a strange problem when programming PLC S7-1200. The system variables are behaving abnormally. I make a simple program using main OB containing 2 networks to see the status of variables "Always TRUE" and "Clock_0.5Hz". But both of them never ON.

I don't think there's another variable overwriting it, there isn't any FC or FB or networks in the program. How can I fix this?

Thank You All.

 

 Thank You,

This has solved my problem