Store entities in stack for undetermined length of time
This block stores up to N entities simultaneously, where N is the Capacity parameter value. The block attempts to output an entity through the OUT port but retains the entity if the OUT port is blocked. If the block is storing multiple entities and no entity times out, then entities depart in a last-in, first-out (LIFO) fashion. If an entity in this block is scheduled to time out, then it might depart prematurely via the optional TO port. The length of time that an entity stays in this block cannot be determined in advance.
The IN port is unavailable whenever this block stores exactly N entities. In this case, the queue is said to be full.
Entity Input Ports
|IN||Port for arriving entities, which will be stored.|
Entity Output Ports
|OUT||Port for departing entities that do not time out while in this block.|
|TO||Port for entities that time out while in this block. You see this port only if you select Enable TO port for timed-out entities. This port must not be blocked when an entity attempts to depart here.|
Signal Output Ports
|Label||Description||Time of Update When Statistic Is On||Order of Update When Entity Departs|
|#d||Number of entities that have departed from this block via the OUT port since the start of the simulation.||After entity departure via the OUT port||3|
|#n||Number of entities currently in the queue.||After entity arrival and after entity departure||2|
|w||Sample mean of the waiting times in this block for all entities that have departed via any port.||After entity departure||1|
|len||Average number of entities in the queue over time, that is, the time average of the #n signal.||After entity arrival and after entity departure.||1|
|#to||Number of entities that have timed out from this block since the start of the simulation.||After entity departure via the TO port||3|
Output signals having the same number in the Order of Update column in the table above are updated in an arbitrary sequence relative to each other; you should not rely on a specific sequence for your simulation results.
The initial output value, which is in effect from the start of the simulation until the first update by the block, is 0 for all signals.
Determines how many entities the block can store at a time. The capacity must be a positive integer or
This option becomes relevant if an entity times out while in this block. Selecting this option provides a TO entity output port through which the timed-out entity departs. If you clear this option in a model that uses timeouts, see the If entity has no destination when timeout occurs parameter of the Schedule Timeout block.
These parameters determine whether the block produces data at signal output ports or omits those ports. For descriptions of the data and ports, see the preceding table, "Signal Output Ports".
Allows you to use the signal output port labeled #d.
Allows you to use the signal output port labeled #n.
Allows you to use the signal output port labeled w.
Allows you to use the signal output port labeled len.
Allows you to use the signal output port labeled #to.