Door control with code entry

Description
This function module implements PIN code-controlled access control with integrated blocking function in case of incorrect entries, logging, automatic door opening time and LED feedback.
The code is written entirely in Structured Control Language (SCL) and can be used directly 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
Pressing the Delete button resets the LED display.
If an incorrect code is entered three or more times – or if the system is in emergency stop mode – the lock mode is automatically activated.
An IEC timer maintains this state for a defined lockout period. During this time, the "Lockout Time Active" LED lights up, and all inputs remain locked.
After the timer expires, the lock mode is released and the failed attempt counter is reset.
Each "Enter " pulse triggers the code check. If the entered digits match one of the stored codes, the door opens for a configurable duration, and the "Access Granted" LED is illuminated.
If the code is incorrect, the failed attempt is counted, the “Access Denied” LED lights up, and the attempt is saved in the log.

Technical details
The Enter and Delete keys are evaluated via edge detection with standard triggers.
Two IEC timers independently control the door opening time and the locking time.
The code check is done by comparing the input with a code array codeList .
A circular log array with index counter stores the last ten entries and their evaluation.
LEDs for access granted , access denied and lock time active provide immediate visual feedback.
The Door Open variable is available for HMI displays or relay outputs.

Possible applications
Ideal for access control in offices, laboratories, industrial facilities or even in private areas.
Can also be used for model projects, training courses or safety demonstrations.
The integrated logging and locking logic makes the system audit-ready and adaptable for reporting applications.

compatibility
The block can run on Siemens S7-1200 and S7-1500 controllers.
Compatible with TIA Portal version V13 and higher – V16 or newer is recommended for full use of all HMI and simulation functions via PLCSIM.

Scope of delivery
You will receive an .scl file with complete declaration of all inputs and outputs, trigger instances, timers, logic fields and LED controls.
The download link is available immediately after purchase.

Support
I am happy to help with adjusting the PIN length, extended log formats, or additional alarm and security features.
Contact via email or through the shop is possible at any time.