SimEvents Diagnostics Pane

Diagnostics Pane Overview

Specify what diagnostic action the application should take, if any, when it detects situations that might cause problems or unexpected results in the simulation.

Configuration

This pane appears only if your model contains a SimEvents® block.

Tips

  • The options are typically to do nothing or to display a warning or an error message.

  • A warning does not terminate a simulation, but an error does.

Attribute output delayed relative to entities

Select the diagnostic action to take if the application detects a situation in which a Get Attribute block updates a signal during entity advancement, but a subsequent block responds to the signal update after the entity has arrived. The application's processing sequence might cause the latter block to process the entity using outdated signal values.

Settings

Default: error

none

The application does not check for this situation.

warning

When the application detects this situation, it displays a warning.

error

When the application detects this situation, it terminates the simulation and displays an error message.

Tip

A Single Server block whose Service time parameter is 0 can address the problem by storing the entity while the latter block responds to the signal update.

Example of Solution

For details, see Use Block Diagrams to Manipulate Attributes.

Alternatively, you might be able to address the problem by using an attribute directly instead of by using the signal output of a Get Attribute block. For an example, see Use a Signal or an Attribute.

Command-Line Information

Parameter: propDiagAttribOutput
Type: double
Value: 0 | 1 | 2
Default: 2

Recommended Settings

ApplicationSetting
Debuggingwarning or error
Efficiencynone

See Also

Response to function call delayed relative to entities

Select the diagnostic action to take if the application detects a situation in which a block issues a function call during entity advancement, but subsequent blocks respond to the function call and its consequences after the entity has arrived. The application's processing sequence might cause subsequent blocks to process the entity using outdated values of a signal whose update is a consequence of the function call.

Settings

Default: error

none

The application does not check for this situation.

warning

When the application detects this situation, it displays a warning.

error

When the application detects this situation, it terminates the simulation and displays an error message.

Tip

A Single Server block whose Service time parameter is 0 can address the problem by storing the entity while subsequent blocks respond to the function call and its consequences.

Example of Solution

Command-Line Information

Parameter: propDiagFcnCallOutput
Type: double
Value: 0 | 1 | 2
Default: 2

Recommended Settings

ApplicationSetting
Debuggingwarning or error
Efficiencynone

See Also

Unexpected Use of Old Value of Signal

Statistical output delayed relative to entities

Select the diagnostic action to take if the application detects a situation in which a block updates a statistical output signal during entity advancement, but a subsequent block responds to the signal update after the entity has arrived. The application's processing sequence might cause the latter block to process the entity using outdated signal values.

Settings

Default: error

none

The application does not check for this situation.

warning

When the application detects this situation, it displays a warning.

error

When the application detects this situation, it terminates the simulation and displays an error message.

Tip

A Single Server block whose Service time parameter is 0 can address the problem by storing the entity while the latter block responds to the signal update.

Example of Solution

For details, see Sequence of Departures and Statistical Updates.

Command-Line Information

Parameter: propDiagStatOutput
Type: double
Value: 0 | 1 | 2
Default: 1

Recommended Settings

ApplicationSetting
Debuggingwarning or error
Efficiencynone

See Also

Unexpected Use of Old Value of Signal

Modification of attribute values used for decision making

Select the diagnostic action to take if the application detects certain situations in which a block modifies an attribute that a subsequent block uses to determine its availability. In some of these cases, internal queries among blocks might result in a decision based on information that changes when the entity actually advances.

Settings

Default: error

none

The application does not check for this situation.

warning

When the application detects this situation, it displays a warning.

error

When the application detects this situation, it terminates the simulation and displays an error message.

Tip

A Single Server block whose Service time parameter is 0 can address the problem by storing the entity while the latter block responds to the signal update.

Example of Solution

Command-Line Information

Parameter: propDiagChangeAttrib
Type: double
Value: 0 | 1 | 2
Default: 2

Recommended Settings

ApplicationSetting
Debuggingwarning or error
Efficiencynone

See Also

Query Whether a Subsequent Block Can Accept an Entity

Identical seeds for random number generators

Select the diagnostic action to take if the application detects that multiple random number generators use the same seed value, which might cause correlations among random processes.

Settings

Default: warning

none

The application does not check for this situation.

warning

When the application detects this situation, it displays a warning.

error

When the application detects this situation, it terminates the simulation and displays an error message.

Tips

  • If you set the parameter to warning, the warning message contains hyperlinks labeled "Randomize" and "Randomize All" that can help you address the problem.

  • The se_randomizeseeds function provides a programmatic way to address the problem.

  • Set the parameter to none if duplicate seeds are intentional in your model. For example, the Comparing Routing PoliciesComparing Routing Policies example implements the same random arrival process multiple times, to compare routing policies.

Command-Line Information

Parameter: propRNGIdenticalSeeds
Type: double
Value: 0 | 1 | 2
Default: 1

Recommended Settings

ApplicationSetting
Debuggingwarning or error
Efficiencynone

See Also

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