# LGF_Impulse (FB / V3.0.1)

Author: Siemens Industry Support

## Short description

This function generates pulses at a given frequency. The pulse is always present for one (control) cycle.

### Block Interface

| LGF_Impulse (FB) |
--- | --- | ---
Real |  |  | frequency |  | impulse |  |  | Bool
|  |  |  |  | countdown |  |  | Time

### Input parameter

Identifier | Data type | Default value | Description
--- | --- | --- | ---
frequency | Real | 0.0 | Clock frequency in Hz

### Output parameter

Identifier | Data type | Description
--- | --- | ---
impulse | Bool | Impulse signal output
countdown | Time | Time until next pulse

## Functional description

The function generates pulses at the output `impulse` with the frequency `frequency`.
The block always begins with a pulse and sets the next pulse after the period that has elapsed.

###### Example

## Change log

Version & Date | Change description
--- | ---
| 01.00.00 | Siemens Industry Online Support
| 19.08.2015 | First released version
| 01.01.01 | Siemens Industry Online Support
| 16.06.2015 | LGF_Impulse calls new LGF_Frequency V1.1.1
| 01.01.02 | Siemens Industry Online Support
| 02.01.2017 | Upgrade: TIA Portal V14 Update 1
| 01.02.00 | Siemens Industry Online Support
| 02.02.2017 | Code optimization: no call of LGF_Frequency Fix at output "countdown"
| 01.02.01 | Siemens Industry Online Support
| 17.08.2018 | Upgrade: TIA V15 Update 2
| 01.02.02 | Siemens Industry Online Support
| 23.11.2018 | Upgrade: TIA V15.1
| 01.02.04 | Simatic Systems Support
| 20.09.2019 | Code refactoring, regions and more comments added
| 03.00.00 | Simatic Systems Support
| 23.04.2020 | Set version to V3.0.0, harmonize the version of the whole library
| 03.00.01 | Simatic Systems Support
| 15.02.2021 | Insert documentation