dear.Sir

I have 1 questions.
When i push switch button program send logic 1 to device but when I don't push switch button program still send logic 1.
I want to know how i can do for when i don't push switch button program send logic 0.

This depends on how you have your tag set. Your Digital Control tag will have a Pulse Duration input box in the I/O tab. If that is set to zero, the tag will write the set value to the address you choose. If there is a pulse defined, the tag will write a 1 (or your defined value) and then a 0. It is common to use two buttons, both having a pulse of 0. One to write a 1 and the other to write a 0. You can define the value to write in the button properties

Does that make sense?