FB_SPEED

Description Function Block

The FB_SPEED function block is used to save the Position input and calculate a speed from it with the specified time interval. The speed at the output is given in increments for each tTimeInterval.

EL6900

The FB_SPEED function block is not supported by the EL6900.

Table 54. VAR_INPUT

Name	Data Type	Initial Value	Description, Parameter Values
`Position`	`LINT`	`0`	Input channel for the calculation of speed Permitted data types: `UINT`, `INT`, `UDINT`, `DINT`
`bOverflowCheck`	`SAFEBOOL`	`FALSE`	`FALSE`: For unsigned types, no overflow is checked. (This means that for the `UINT` type the value `0` follows the position `0xFFFFFF` (or vice versa) and for the UDINT type the value `0` follows the position `0xFFFFFFFFFF` (or vice versa). `TRUE`: Unsigned types are checked for overflow. Only a constant value is permitted (no variable)
`tTimeInterval`	`SAFETIME`	`TIME#0ms`	Time interval for the calculation of speed.

Name

Data Type

Initial Value

Description, Parameter Values

Position

LINT

0

Input channel for the calculation of speed

Permitted data types: UINT, INT, UDINT, DINT

bOverflowCheck

SAFEBOOL

FALSE

FALSE: For unsigned types, no overflow is checked. (This means that for the UINT type the value 0 follows the position 0xFFFFFF (or vice versa) and for the UDINT type the value 0 follows the position 0xFFFFFFFFFF (or vice versa).

TRUE: Unsigned types are checked for overflow.

Only a constant value is permitted (no variable)

tTimeInterval

SAFETIME

TIME#0ms

Time interval for the calculation of speed.

Table 55. VAR_OUTPUT

Name	Data Type	Initial Value	Description, Parameter Values
`Speed`	`SAFEUSINT`	`0`	Output with the calculated speed Permitted data types: `UINT`, `INT`, `UDINT`, `DINT`. The data type must be selected according to the input data types.
`bError`	`SAFEBOOL`	`FALSE`	`TRUE`: The `Speed` output has an overflow or underflow. `FALSE`: No error has occurred.

Name

Data Type

Initial Value

Description, Parameter Values

Speed

SAFEUSINT

0

Output with the calculated speed

Permitted data types: UINT, INT, UDINT, DINT. The data type must be selected according to the input data types.

bError

SAFEBOOL

FALSE

TRUE: The Speed output has an overflow or underflow.

FALSE: No error has occurred.