Function Block CTUD

The Function Block CTUD counts up and down.

Input CU

On a positive edge, the output CV is counted up.

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 of the input PV.

Input RESET

If the input is true, the output CV is reset to 0. This input has priority over LOAD.

Input PV

Defines the limit value for the output QU as a number. The counter CV is not limited upwards in this process.

Simultaneously defines the initial value for the output CV as a number.

Output QU

The output is true when the output CV is greater than or equal to PV.

Output QD

The output is true when the output CV equals 0.

Output CV

The output defines the counter.