Cold room control with temperature monitoring

Description
The FB_CoolingController function block reliably controls temperature and ventilation in compact systems such as control cabinets, server rooms, or small cooling lines. It combines automatic cooling control with hysteresis, door monitoring, manual override, sensor testing, and alarm functions—all in one SCL module, ready for use in the Siemens TIA Portal.

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
Right at the start, the component checks whether the measured temperature value is within the permissible range (between -5 °C and +15 °C, or in tenths of a degree). If this is not the case, a sensor alarm is triggered. Cooling is deactivated as a precaution, while the fan is activated to prevent overheating.

In automatic mode, a hysteresis control takes over the control:

• If the setpoint is exceeded , the cooling switches on.
• If the temperature falls below the setpoint minus hysteresis, the cooling is switched off again.

In manual mode, a single press of a button is enough to activate the cooling directly – regardless of the temperature value.

Door open? No problem: If the module detects an open door, it automatically switches on the fan to prevent heat buildup – even if the cooling system itself is not active.

If the temperature exceeds a critical threshold, an additional alarm is triggered.

Technical details

• Sensor validation protects against incorrect values
• Manual control only when automatic mode is deactivated
• Hysteresis control via setpoint and hysteresis width (both variable)
• Door signal acts directly on fan output
• Separate outputs for sensor errors and temperature alarms
• Status output “Status Cooling” for visualization or control systems

Possible applications
Ideal for temperature control in:

• Control cabinets or IT racks
• measurement and laboratory systems
• Small systems with independent cooling control
• Training environments to convey practical rule and security logic

compatibility
Runs on Siemens S7-1200 and S7-1500
Developed for TIA Portal from version V13
For PLCSIM, HMI visualization or SCADA, V16 or higher is recommended

Scope of delivery
You will receive an .scl file with:

• Clearly commented inputs and outputs
• Hysteresis control
• Door monitoring
• Manual/automatic logic
  Notes on parameterization (e.g. for setpoint temperature or alarm limits) The download link is available immediately after purchase.

Support
I am happy to support you with:

• The adjustment of control parameters
• Integration into existing systems
• The extension of security or visualization functions
  Simply report it by email or via shop support.