Main Content

TOF

Timer Off Delay

  • Library:
  • TOF block

Description

The TOF block implements the TOF ladder instruction. When the rung conditions are true, the block accumulates time until:

  • The timer is disabled

  • The timer completes

Ports

Input

expand all

Controls the execution of the block. EnableIn reflects the rung state preceding the block. If the rung state preceding the block is false, EnableIn is false, the block does not execute and the outputs are not updated.

Output

expand all

By default, EnableOut follows the state of EnableIn. If the EnableIn input to the block is false, the logic implemented by the block is not executed and EnableOut signal is set to false.

Parameters

expand all

Specify the timer parameters in the format of tags. In Ladder Diagrams, tags (variables) are used for representing all inputs, outputs, and internal memory with attributes such as Data Type, Initial Value, and size. To change the attributes of the Operand Tag, open the Program Variables table within the Ladder Diagram Program block. The Data Type of the timer tag is of the Bus:TIMER type with its initial value specified as a structure containing the following fields:

FieldDescriptionDefault Value
PRE

The preset value specifies the value (1 millisecond units) which the accumulated value must reach before the instruction indicates it is done

0
ACC

The accumulated value specifies the number of milliseconds that have elapsed since the TOF instruction was enabled.

0
EN

The enable bit contains rung-condition-in when the instruction was last executed.

0
TT

The timing bit when set indicates the timing operation is in process.

0
DN

The done bit when set indicates the timing operation is complete (or paused).

0

Programmatic Use

Block Parameter: PLCOperandTag
Type: character vector
Value: character vector
Default: 'T'

See Also

| | | |

Introduced in R2019a