I understand that you want to model the 'External Interrupt' block which activates the Function Call Subsystem, in such a way that it allows for deactivation of the subsystem output until the next interrupt.
To do this, I recommend adding an Input port to the 'External Interrupt' and incorporating input logic to control the interrupt accordingly. You can achieve this by checking the 'Add simulation input port' option in Block Parameters of the 'External Interrupt' block. This will enable the 'SimIRQ' block input. In simulation, the block triggers the downstream function-call subsystem only if 'SimIRQ' is True.
Please refer to the following MathWorks example, which demonstrates a similar approach: https://www.mathworks.com/help/simulink/supportpkg/arduino_ref/trigger-downstream-function-call-subsystem-using-arduino-external-interrupt-block.html
I hope this helps!
