FB_TOF

Description Function Block

The FB_TOF function block is used to implement a switch-off delay. A logic 1 at the bTofIn input is extended by the set time forwarded to the output. If the input is set to 1 again before the switch-off delay time is reached, then the output remains switched on.

Table 26. VAR_INPUT

Name	Data Type	Initial Value	Description, Parameter Values
`bTofIn`	`SAFEBOOL`	`FALSE`	Input channel: The Negation command can be used to specify whether a normally closed contact (safe state is requested at logic `0`) or a normally open contact (safe state is requested at logic `1`) is linked to this input.
`tSwitchOffTime`	`SAFETIME`	`TIME#0ms`	Switch-off delay time For the EL6900 controller, the time base of `tSwitchOffTime` is 100 ms. The minimum value is 1 * 100 ms = 0.1 seconds; the maximum value is 6000 * 100 ms = 600 seconds. With the EL6910/EK1960 controller, the time base is determined automatically: If the value of `tSwitchOffTime` is divisible by 10, then the time base of 10 ms is selected. The minimum value is 1 * 10 ms = 0.01 seconds; the maximum value is 60000 * 10 ms = 600 seconds. If the value of `tSwitchOffTime` is not divisible by 10, then the time base 1 ms is selected. The minimum value is 1 * 1 ms = 0.001 seconds; the maximum value is 60000 * 1 ms = 60 seconds.

Name

Data Type

Initial Value

Description, Parameter Values

bTofIn

SAFEBOOL

FALSE

Input channel: The Negation command can be used to specify whether a normally closed contact (safe state is requested at logic 0) or a normally open contact (safe state is requested at logic 1) is linked to this input.

tSwitchOffTime

SAFETIME

TIME#0ms

Switch-off delay time

For the EL6900 controller, the time base of tSwitchOffTime is 100 ms. The minimum value is 1 * 100 ms = 0.1 seconds; the maximum value is 6000 * 100 ms = 600 seconds.

With the EL6910/EK1960 controller, the time base is determined automatically:

If the value of tSwitchOffTime is divisible by 10, then the time base of 10 ms is selected. The minimum value is 1 * 10 ms = 0.01 seconds; the maximum value is 60000 * 10 ms = 600 seconds.
If the value of tSwitchOffTime is not divisible by 10, then the time base 1 ms is selected. The minimum value is 1 * 1 ms = 0.001 seconds; the maximum value is 60000 * 1 ms = 60 seconds.

Table 27. VAR_OUTPUT

Name	Data Type	Initial Value	Description, Parameter Values
`bTofOut`	`SAFEBOOL`	`FALSE`	Output channel: The safe state corresponds to logic `0`.