Equipments (Devices) > CFW501 > Ladder > Timer

Timer block that, when energized, disables the output after a delay set by PT.

Ladder Representation

TOF_block

Block Structure

Variable Type	Name	Data Type	Description
VAR_INPUT	IN	BOOL	Block enabling
	PT	WORD UINT DWORD1 UDINT1	Delay of output deactivating
	TIMEBASE	WORD	Time base for PT and ET
VAR_OUTPUT	Q	BOOL	Block output
VAR_OUTPUT	ET	WORD UINT DWORD1 UDINT1	Counter elapsed time
VAR	TOF_INST_0	TOF	Instance of access to block structure

NOTE!

1. In CFW300 and CFW100, the PT and ET field types can only be WORD or UINT.

2. Some devices allow you to configure user parameters, but these need to be configured for use in the fields PT and ET, where it is necessary to select a compatible data type as shown in table above. For more information refer to the corresponding topic;

3) The TIMEBASE field may vary depending on the device used.

Operation

While the IN input is TRUE, the Q output is also TRUE and ET also receives the value zero.

On the negative transition edge in IN, counting is triggered and ET is incremented according to TIMEBASE. When ET equals PT, the Q output goes to state FALSE until IN revolutions to FALSE.

Compatibility

Device	Version
PLC300	1.50 or higher
SCA06	2.00 or higher

Block Flowchart

TOF_flowchart

Operation Diagram

hardwaretimertof_fig2

Example in Ladder

TOF_example01

The above example disables the DO1 output to identify a low level in DI1 for 12 seconds, remaining disabled until DI1 again be TRUE.

Example in ST

The example below displays the instructions for applying the example above in the ST language.

VAR

PRESET : UINT := 12;

ELAPSED : UDINT;

TOF_INST_0 : FB_TOF;

END_VAR

TOF_INST_0.IN := DI1;

TOF_INST_0(PT:=PRESET, TIMEBASE:=2); // TIMEBASE according to

ELAPSED := TOF_INST_0.ET; // the device used

DO1 := TOF_INST_0.Q;