Extended access control functions

The networked control and monitoring systems of the 500/500DC series can be equipped with RFID card readers or electronic key readers for access control of IT rooms. In the system tree under "1wire," the "iButton" element is used to control access to the system (via iButton Key or RFID ID card).

If no electronic key or RFID card is connected, the "Reader" element is in the "not connected" state.

These events with unlimited duration (button activation) are best managed using a trigger function. Please create a trigger called "Trigger Valid Key" that will be activated when a valid key is connected to the reader. Also create a logic function for this event called "Logic Valid Key".

Now create the main logic scheme. First, the trigger will be deactivated after 10 seconds to prevent double triggering. Second, a pulse will be triggered at the control output of the electronic lock. Set the desired pulse duration in the properties of the corresponding element (e.g., 12V relay output). If you have connected a USB camera to an Ethernet-based measurement and monitoring system, video recording can also be started.

To assign a cyclical pattern (Normal => Alarm => Normal…) to the trigger function, we need to create a so-called "helper trigger" that activates and deactivates the trigger. Please create the "helper_logic" as shown in the image below (please click on the image for a larger view). The trigger named "helper_trigger" is activated as soon as a valid key is connected (iButton is set to "normal" in the web interface). After 5 seconds, the "helper_trigger" trigger function is automatically deactivated.

Now create the main trigger (main_trigger) and its associated logic. Note that the logic is only activated when the helper trigger (helper_trigger) is deactivated. Therefore, the main trigger will only fire once every 5 seconds. There is no conflict between the logic for turning the main trigger on and off.