Function Block CTD

The Function Block CTU counts down to 0.

Input CD

On a positive edge, the output CV is counted down to 0.

Input LOAD

If the input is true, the output CV is reset to the value from the input PV.

Input PV

Defines the initial value for the output CV as a number.

Output Q

The output is true when the output CV equals 0.

Output CV

The output defines the counter.