I have folowing code in Plc(Simatic S7)
SP_Change is reset after 3 seconds.
Frequency of SP change is 25-30 seconds.
Folowing massage configured in WinCC:
"Set point change Old_Value/New_Value".
Message is triggered by #SP_Cange bit.
Usually everything works as expected and i get messages like
"Set point change 40/41".
But sometimes i get messages with 0/0 or same value like 40/40.
I fail to understand why this is happening.
Code:
L #dwControl_Struct.Set_point
T #wOld_Value
L 1
L #dwControl_Struct.Set_point
+I
T #dwControl_Struct.Set_point
T #wNew_Value
S #SP_Change
Frequency of SP change is 25-30 seconds.
Folowing massage configured in WinCC:
"Set point change Old_Value/New_Value".
Message is triggered by #SP_Cange bit.
Usually everything works as expected and i get messages like
"Set point change 40/41".
But sometimes i get messages with 0/0 or same value like 40/40.
I fail to understand why this is happening.