Video surveillance trigger

Description
You're looking for an SCL function block (FB_MonitoringTrigger) that triggers video, light, and alarm display when motion is detected, a door is contacted, or a manual button is pressed. In the event of a fault, all functions are disabled and the HMI display shows "BLOCKED." It can be run directly in the Siemens TIA Portal for indoor and outdoor use.

Note: All modules are designed exclusively as a learning and optimization basis and are not approved for live operation. System modules, in particular, must be finally tested and commissioned by qualified personnel before productive use.

How it works

1. Fault check: If TRUE → Video, light and alarm off, HMI "BLOCKED", RETURN
2. Edge detection (movement, door contact, button) via IEC function blocks
3. On positive edge → set trigger, report source to HMI, video+alarm on
4. Night mode active → additionally switch on light
5. Pulse timer PT=T#5s starts → reset video, light and trigger after 5 s

Technical details
• Inputs: Fault, movement, door contact, manual button (cyclic)
• Three IEC edge detectors, one IEC PT timer (5 s)
• Internal flag trigger/trigger active, variable source for HMI
• RETURN in case of failure aborts all actions immediately

Possible applications
• Burglary and access monitoring at entrances, halls or parking lots
• Alarm systems in production areas
• Retrofitting existing systems or training laboratories

compatibility
• Siemens S7-1200 & S7-1500
• TIA Portal V13 or higher; recommended V16+ with PLCSIM

Scope of delivery
• .scl file with declarations of all inputs/outputs, edge detectors, timers and HMI variables
• Instant download link after purchase

Support
I can help with additional sensor sources, video storage logic, or HMI integration. Contact me via shop message or email.