Dosing system for liquids

Description

This compact function block provides reliable, simple dosing control with fill level monitoring and integrated dry-run protection. The code, written in Structured Control Language (SCL), is ready for immediate use in the Siemens TIA Portal—perfect for smaller mixing or filling systems.

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

The process starts with a security query:
As soon as an emergency stop or stop signal is detected, the module immediately sets an alarm flag, closes the dosing valve and puts the system into the safe idle state (step 0).

The current fill level is then checked:
If the actual quantity is below the defined minimum quantity , an alarm is also triggered and the cycle is stopped.

Only when automatic mode is activated and a start button has been pressed does the dosing valve open and dosing begins.
As long as the actual quantity is less than the setpoint , the valve remains open and the status “dosing active” is set.
As soon as the setpoint is reached or exceeded , the valve is automatically closed, the status is reset and the control returns to the initial state.

Technical details

• Safety priority : Emergency stop, stop signal and dry-running protection lead to immediate shutdown of the valve
• Two-step state machine : Idle (closed) and dosage active (open)
• Level control : Direct comparisons without external timers – for fast, lean processes
• TRUE/FALSE signals for VentilAuf , StatusDosierung , Alarm – ideal for HMI or relay output
• Alarm variable is automatically set in all error or abort cases

Possible applications

Ideal for:

• Dosing tasks in small productions , laboratories, pilot plants
• Filling small containers , dosing liquids, powders or granules
• Training environments for introducing FSM-controlled logic and security concepts

compatibility

• Runs on Siemens S7-1200 and S7-1500
• Compatible from TIA Portal version V13
• For simulation and visualization: recommended from version V16 (incl. PLCSIM)

Scope of delivery

You get:

• An .scl file with complete declaration of all inputs and outputs
• State machine (FSM), comparisons for actual/target/minimum values
• Commented header with instructions for adjusting safety and target values
• The download link is available immediately after purchase

Support

I am happy to help you with:

• The adjustment of filling quantities or limit values
• The integration into your existing system structure
• The extension to HMI interfaces , alarms or digital evaluations

Simply contact us by email or directly via shop support – I will find the right solution.