- The segment of the block calculating "Period" is using a "Triggered Subsystem". Due to this, when no trigger signal is found, the block output is the previously calculated result at the previous trigger.
- The segment of the block calculating "Duty Cycle" uses an "Enabled Subsystem" in which the Outport value is set to be "held" in "Output when disabled" field, which results in holding the output value.
- "Triggered Subsystem" : https://www.mathworks.com/help/releases/R2020b/simulink/ug/triggered-subsystems.html
- "Enabled Subsystem" : https://www.mathworks.com/help/releases/R2020b/simulink/ug/enabled-subsystems.html