FB: Monitor Physical Pulse Button - v1.3

This function block monitors a physical pulse button and generates a timed output pulse on the positive edge (button press). It also monitors for a stuck-button condition via a configurable watchdog.

Use Cases

• Start/stop pushbuttons on a physical panel.
• Any momentary input where a clean, debounced pulse output is required.

Dependencies

Type	Name	Version
function	TP_TIME	Siemens FB
function	TON_TIME	Siemens FB

Parameters

Function

Parameter	Declaration	Type	Init. value	Description
button	Input	Bool	—	IW: 1= Button is pressed
WATCHDOG_TIME	Input Retain	Time	T#10s	IR: Watchdog time. 0= Disabled; >0= Maximum allowed press duration
PULSE_TIME	Input Retain	Time	T#500ms	IR: Output pulse duration
Q	Output	Bool	—	OR: 1= Pulse output (active for PULSE_TIME)
PE	Output	Bool	—	OR: 1= Positive edge detected (one-scan pulse)
a2w_1_watchdog	Output	Bool	—	OR: 1= Alarm warning — button held longer than WATCHDOG_TIME