FB: Monitor Physical Acknowledgement Button - v1.1
This function block monitors a physical acknowledgement button and generates a pulse output on the negative edge (button release). It also monitors for a stuck-button condition via a configurable watchdog.
Use Cases
Section titled “Use Cases”- Alarm acknowledgement button on a physical panel.
- Any input where the action should trigger on release rather than press.
Dependencies
Section titled “Dependencies”| Type | Name | Version |
|---|---|---|
function | TP_TIME | Siemens FB |
function | TON_TIME | Siemens FB |
Parameters
Section titled “Parameters”Function
Section titled “Function”| Parameter | Declaration | Type | Init. value | Description |
|---|---|---|---|---|
button | Input | Bool | — | IR: 1= Button is pressed |
WATCHDOG_TIME | Input Retain | Time | T#10s | IR: Watchdog time. 0= Disabled; >0= Maximum allowed press duration |
ACKN_TIME | Input Retain | Time | T#500ms | IR: Output pulse duration on negative edge |
Q | Output | Bool | — | OR: 1= Acknowledgement pulse (active for ACKN_TIME) |
a2w_1_watchdog | Output | Bool | — | OR: 1= Alarm warning — button held longer than WATCHDOG_TIME |