# LGF_PulseRelay (FB / V3.0.1)

Author: Siemens Digital Industry

## Short description

This block corresponds to an impulse relay or a toggle flip-flop including set and reset input. Pulse relay, Surge relay, Toggle-Flip-Flop, Frequency divider `reset` is leading / prior to `set` or `trigger`

### Block Interface

| LGF_PulseRelay (FB) |
--- | --- | ---
Bool |  |  | trigger |  | out |  |  | Bool
Bool |  |  | set |  |  |  |  |
Bool |  |  | reset |  |  |  |  |

### Input parameter

Identifier | Data type | Default value | Description
--- | --- | --- | ---
trigger | Bool | FALSE | Trigger to toggle output signal (rising edge)
set | Bool | FALSE | Set output signal. rising edge
reset | Bool | FALSE | Reset signal, rising edge (prior to set)

### Output parameter

Identifier | Data type | Description
--- | --- | ---
out | Bool | Ooutput signal

## Functional description

Figure: LGF_PulseRelay Signal diagram

1. Each rising edge of the input `trigger` changes the Boolean value of the output `out`.
2. Each rising edge of the input `set` sets the Bboolean value of the output `out` to `TRUE`.
3. Each rising edge of the input `reset` sets the Boolean value of the output `out` to `FALSE`.
4. If the inputs `set` and `reset` are set in the same cycle, the `reset` input has priority.

The block can also be used as a frequency divider. If the input `trigger` is supplied with a fixed frequency, the output `out` delivers half the frequency.

## Change log

Version & Date | Change description
--- | ---
| 01.00.00 | Siemens Industry Online Support
| 06.06.2015 | First released version
| 01.00.01 | Siemens Industry Online Support
| 02.01.2017 | Upgrade: TIA V14 Update 1
| 01.00.02 | Siemens Industry Online Support
| 02.01.2017 | Comment correction
| 01.00.03 | Siemens Industry Online Support
| 17.08.2018 | Upgrade: TIA V15 Update 2
| 01.00.04 | Siemens Industry Online Support
| 23.11.2018 | Upgrade: TIA V15.1
| 01.00.05 | Simatic Systems Support
| 24.05.2019 | Refactoring and performance improvement add ENO handling
| 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
| 19.01.2021 | Insert documentation