By checking the Maximum number of signals simultaneously processed checkbox within the Discrete Change Delay dialog, you can specify a capacity for the Delay in the input field directly below the checkbox.
For example, if you specify this value as 3, the element can only have three signals in transit at any given time. Any other signals that it receives are placed in a queue. Signals in the queue must wait for one of the signals in transit to be emitted before they can begin to traverse the delay. GoldSim keeps track of the number of signals in transit (Num_in_Transit) and the number of signals in the queue (Num_in_Queue).
Note: The specified capacity can be a number, a link or an expression. It must be dimensionless and non-negative. GoldSim automatically truncates the value to an integer.