SimEvents^®

Entity-Based Function-Call Event Generator

Event-Based Entity Generator - Generate entity upon signal-based event or function call

Library

Generators / Entity Generators

Description

This block is designed to generate entities when events of a specified type occur.

When to Generate Entities	Generate entities upon Value
Each time the application recomputes and outputs the value of a signal	`Sample time hit from port ts`
Each time an input signal has a trigger edge	`Trigger from port tr`
Each time an input signal changes its value	`Change in signal from port vc`
Each time an input signal generates a function call	`Function call from port fcn`

Note An exceptional case is when the block temporarily suspends its normal entity-generation behavior. See the description of the Delay first pending entity option in Responding to Blockage at the Entity Output Port.

Responding to Blockage at the Entity Output Port

Using the Allow OUT port blocking and optional Response during blockage period parameters, you can choose how this block responds when the subsequent entity input port is not available to accept the newly generated entity. The possible responses are in the table below.

Response to Blockage	Parameter Values
Error message	Clear the Allow OUT port blocking check box.
The block discards all entities generated while the OUT port is blocked. Such entities do not depart from the block.	Select Allow OUT port blocking and set Response during blockage period to `Discard generated entities`
The block holds one generated entity and temporarily suspends the generation of additional entities. When the subsequent entity input port becomes available, this block outputs the held entity and resumes normal operation.	Select Allow OUT port blocking and set Response during blockage period to `Delay first pending entity`

Ports

Signal Input Ports

Label	Description
ts	Signal whose updates indicate when to generate entities. This port appears only if you set Generate entities upon to `Sample time hit from port ts`.
tr	Trigger signal whose edges indicate when to generate entities. This port appears only if you set Generate entities upon to `Trigger from port tr`.
vc	Signal whose numerical changes in value indicate when to generate entities. This port appears only if you set Generate entities upon to `Change in signal from port vc`.
fcn	Function-call signal that indicates when to generate entities. This port appears only if you set Generate entities upon to `Function call from port fcn`.

Entity Output Ports

Label	Description
OUT	Port through which generated entities depart.

Signal Output Ports

Label	Description	Time of Update When Statistic Is On	Order of Update
#d	Number of entities that have departed from this block since the start of the simulation.	After entity departure	3
pe	A value of 1 indicates when the block tries and fails to output an entity.	After entity generation if OUT port is blocked, and when entity departure is imminent in all cases	1
w	Average intergeneration time, in seconds, for all pairs of successive entities that have departed from this block. The signal value is 0 before the second entity departure.	After entity departure	2

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.

Dialog Box

Entity type: The blank type includes no attributes. The standard type includes attributes called Priority and Count with default values of 10 and 0, respectively.
Allow OUT port blocking: If you do not select this option, the simulation halts with an error message if the subsequent entity input port is not available to accept an entity when this block generates it.
Response during blockage period: Determines how the block responds if a generated entity cannot depart immediately because the entity input port of the subsequent block is unavailable; see Responding to Blockage at the Entity Output Port. This field appears only if you select Allow OUT port blocking.

Entity Generation Tab

Generate entities upon: The type of event that indicates when the block should generate an entity.
Trigger type: Determines whether rising, falling, or either type of trigger edge causes an entity generation. This field appears only if you set Generate entities upon to Trigger from port tr.
Type of change in signal value: Determines whether rising, falling, or either type of value change causes an entity generation. This field appears only if you set Generate entities upon to Change in signal from port vc.
Resolve simultaneous signal updates according to event priority: Select this option to explicitly prioritize the entity-generation event, relative to other simultaneous events in the simulation. If you do not select this option, the event has priority SYS1 on the event calendar. For details, see Choosing How to Resolve Simultaneous Signal Updates.
Event priority: The priority of the entity-generation event, relative to other simultaneous events in the simulation. For details, see Specifying Event Priorities to Resolve Simultaneous Signal Updates. This field appears only if you select Resolve simultaneous signal updates according to event priority.
Generate entity at simulation start: If you select this option, the block generates the first entity when the simulation begins. Otherwise, the block generates the first entity upon the first update of the ts signal at a nonzero value of time. This field appears only if you set Generate entities to Sample time hit from port ts.
Allow entity generation at simulation start: If you select this option, the block responds to function calls at the starting time of the simulation. Otherwise, the block responds only to function calls at subsequent times. This field appears only if you set Generate entities upon to Function call from port fcn.

Statistics Tab

These parameters determine whether certain ports produce data throughout the simulation, produce data only when you stop or pause the simulation, or are omitted from the block. For descriptions of the affected ports, see the "Signal Output Ports" table above.

Number of entities departed: Controls the presence and behavior of the signal output port labeled #d.
Status of pending entity departure: Controls the presence and behavior of the signal output port labeled pe.
Average intergeneration time: Controls the presence and behavior of the signal output port labeled w.