Correct using "Switch"

Hello, I use Tia Portal v11 Basic. In KTP600 Basic Panel I use element “switch” to control FBs Valves and Pumps in program, so i set bits in the my hmi-plc tag “Control_Valve”(byte) with SetBitinTag (on “Switch ON”) and ResetBitinTag (on “Switch Off”) . Byte “Control_Valve” declared in “Input” FB’s area. The problem: it’s not working, then I typed the button on screen, there is no result in PLC.

But!! According to the variables limits for my panel (500), I have not free space to make Tag Connection for control “Switch” , and do not use them. In fact I don't know for what it there.

Or maybe i have to declare tag “Control_Valve” in FB's "InOut".

Thanks!