Vacuum packaging system

Description
The FB_VacuumWeldingStation function block controls the entire vacuum welding process: vacuuming, welding, and subsequent venting. Safety checks for open lids or emergency stop, product and pressure monitoring, and cycle counting are integrated. The block runs directly in the Siemens TIA Portal and provides the current status at any time via an HMI variable.

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. Safety check : If Stop = TRUE or LidClosed = FALSE, the vacuum pump, welding and venting are stopped, an alarm and error are set, StatusText = "Safety stop or lid open", and the logic is aborted via RETURN.
2. Cycle start : A positive edge at the start input (start from FALSE to TRUE) when ProductDetected = TRUE and Error = FALSE sets step = 1.
3. Vacuum phase (step 1) : VacuumPump = TRUE until PressureOK = TRUE. Then step = 2.
4. Welding phase (step 2) : Welding = TRUE for #WeldDuration (TON timer), StatusText = "Weld in progress...". After Timer.Q → Welding = FALSE, Step = 3.
5. Ventilation phase (step 3) : Ventilate = TRUE for #VentDuration (TON timer). After expiration → Ventilate = FALSE, CycleCounter++, StatusText = "Cycle completed - ready", step = 0.
6. Acknowledgement : Acknowledge = TRUE clears alarm and error, StatusText = “Error acknowledged – ready”.

Technical details
Inputs: Stop (BOOL), Lid Closed (BOOL), Start (BOOL), Product Detected (BOOL), Print OK (BOOL), Acknowledge (BOOL)
Outputs: Vacuum Pump, Welding, Ventilation, Alarm, Error (each BOOL), Status Text (STRING), Cycle Counter (INT)
Timer instances: WeldTimer (TON, PT = #WeldingDuration), TunnelTimer (TON, PT = #VentilationDuration)
Edge detection: StartEdge = Start AND NOT StartOld
Control: CASE structure on INT variable step; RETURN terminates all actions immediately in case of security violations

Possible applications
Application in food or pharmaceutical packaging lines for vacuum sealing, retrofitting into existing packaging machines for quality assurance, as well as in training and demonstration systems for PLC-controlled packaging processes.

compatibility
Runs on Siemens S7-1200 and S7-1500 controllers and is compatible with TIA Portal version V13 and higher. For comprehensive HMI integration and PLCSIM simulation, TIA Portal V16 or higher is recommended.

Scope of delivery
You will receive an .scl file with declarations of all inputs and outputs, timer instances, CASE logic, and feedback parameters. Header comments contain the author, website, email address, and instructions for adjusting welding and ventilation times. The download link will be available immediately after purchase.

Support
I'm happy to help with customizing welding and ventilation times, integrating additional safety features, or HMI layouts. Contact me via shop message or email for customized enhancements.