I want to plot the minimum delay of an entity over time in a M/M/1 queueing system. This is how I have set up my simulation
My entities have 2 attributes, start_time and rtt. The start_time is initialized (using the start_timer() function) to the current simulation time when entity is generated. Upon service completion, the rtt is computed as the difference between the current simulation time and start time (using the total_delay() function). I am then using a readily available block to extract the rtt attribute, after which I am keeping a running minimum of the rtt using this feedback mechanism (initial condition for the running minimum is inf). However, the probe always shows a 0 signal. Where am I making a mistake? In general, how do I extract entity attributes to either (a) use as inputs to any generic simulink or matlab function, or (b) save to the workspace? Thanks.