TOF / TOFR

 Function Block - Off timer.

Inputs

Input	Data Type	Range	Unit	Default	Description
IN	BOOL	FALSE, TRUE			Timer command.
PT	TIME				Programmed time.
RST	BOOL	FALSE, TRUE			Reset (TOFR only).

Outputs

Output	Data Type	Range	Unit	Description
Q	BOOL	FALSE, TRUE		Timer elapsed output signal.
ET	TIME			Elapsed time.

Remarks

• TOFR is same as TOF but has an extra input for resetting the timer.
• The timer starts on a falling pulse of IN input.
  • It stops when the elapsed time is equal to the programmed time.
• A rising pulse of IN input resets the timer to 0 (zero).
• The output signal is set to TRUE when the IN input rises to TRUE.
  • It is reset to FALSE when the programmed time is elapsed.

Time Diagram

Figure 1: Time Diagram

FBD Language Example

FFLD Language Example

• In the FFLD Language, the input rung is the IN command.
  • The output rung is Q the output signal.

IL Language Example

Not available.

ST Language Example

(* MyTimer is a declared instance of TOF function block *)
MyTimer (IN, PT);
Q := MyTimer.Q;
ET := MyTimer.ET;

See Also

• blink
• TON
• TP / TPR