Collaboration diagram for WatchdogBlocks:

Watchdog Blocks

Description

Using the watchdog block group you can establish a mechanism between your application and the firmware in order to react to exceptions or problems within your client program execution.

The following steps are necessary:

Setup the watchdog and specify the timeout in milliseconds as well as the action to be taken when the timeout is reached.
Start the watchdog.
Reset the watchdog on a cyclic time basis that is lower than the specified timeout. As soon as you do not reset the watchdog in time, it will execute the action as specified during the setup. E.g. stop the PLC or restart the device.

More Information

For more information, refer to mlpiCore documentation: WatchdogLib.

Copyright

m4SWatchdogGetState

Watchdog Block: Read actual watchdog state.

Description

This block reads the actual watchdog state from the MLPI target. If the watchdog fired, the state will remain equal until the watchdog is restarted with a rising edge at the input bWatchdogOn at the block m4SWatchdog.

Block Inputs

connection defines the connection that will be used. The input must be a scalar uint32 value provided by m4SApiConnect.

result defines if the block will be executed. The input must be a scalar int32 value. The block will not be executed if this value is negative. For negative values the input result is directly fed through to the output result.

Block Outputs

connection contains the connection identifier. The input port connection is fed through to this output. The default value of this port is 0.

result contains the return value of the block. The output is a scalar int32 value. If the output is negative other outputs are invalid. The default value of this output is 0. For details refer to the section Error Identification and Handling in Fundamentals of MLPI Programming.

state contains the watchdog state. The output is a scalar uint32 value. The default value of this port is 0.

Parameters and Dialog Box

Sample time (-1 for inherited) specifies the time interval between samples. To inherit the sample time, set this parameter to -1. This block supports discrete sample time, but not continuous sample time.

Characteristics

Direct Feedthrough	Yes
Sample Time	Fixed Step

Example Model

Here you will find instructions to use the examples.

The following example is available in the folder ./mlpi/mlpi4Simulink/blocks:

m4SWatchdog_Sample.mdl

m4SWatchdogReset

Watchdog Block: Reset watchdog timer.

Description

This block resets the watchdog timer. The watchdog timer has to be reset before the watchdog fires. The timeout has to be set before starting the watchdog timer using block m4SWatchdogSetup.

Block Inputs

connection defines the connection that will be used. The input must be a scalar uint32 value provided by m4SApiConnect.

result defines if the block will be executed. The input must be a scalar int32 value. The block will not be executed if this value is negative. For negative values the input result is directly fed through to the output result.

Block Outputs

connection contains the connection identifier. The input port connection is fed through to this output. The default value of this port is 0.

result contains the return value of the block. The output is a scalar int32 value. If the output is negative other outputs are invalid. The default value of this output is 0. For details refer to the section Error Identification and Handling in Fundamentals of MLPI Programming.

Parameters and Dialog Box

Sample time (-1 for inherited) specifies the time interval between samples. To inherit the sample time, set this parameter to -1. This block supports discrete sample time, but not continuous sample time.

Characteristics

Direct Feedthrough	Yes
Sample Time	Fixed Step

Example Model

Here you will find instructions to use the examples.

The following example is available in the folder ./mlpi/mlpi4Simulink/blocks:

m4SWatchdog_Sample.mdl

m4SWatchdogSetup

Watchdog Block: Setup watchdog functionality.

Description

This block initializes or changes the watchdog functionality.

Block Inputs

connection defines the connection that will be used. The input must be a scalar uint32 value provided by m4SApiConnect.

result defines if the block will be executed. The input must be a scalar int32 value. The block will not be executed if this value is negative. For negative values the input result is directly fed through to the output result.

timeout defines the time for the watchdog in milliseconds. The timeout is checked each millisecond. The input must be a scalar uint32 value.

Block Outputs

connection contains the connection identifier. The input port connection is fed through to this output. The default value of this port is 0.

result contains the return value of the block. The output is a scalar int32 value. If the output is negative other outputs are invalid. The default value of this output is 0. For details refer to the section Error Identification and Handling in Fundamentals of MLPI Programming.

Parameters and Dialog Box

Watchdog action specifies the action that will be taken if the watchdog timer expires. The action must be a MlpiWatchdogAction.

Sample time (-1 for inherited) specifies the time interval between samples. To inherit the sample time, set this parameter to -1. This block supports discrete sample time, but not continuous sample time.

Characteristics

Direct Feedthrough	Yes
Sample Time	Fixed Step

Example Model

Here you will find instructions to use the examples.

The following example is available in the folder ./mlpi/mlpi4Simulink/blocks:

m4SWatchdog_Sample.mdl

m4SWatchdog

Watchdog Block: Activate watchdog.

Description

This block starts the watchdog supervision in the MLPI target.

Block Inputs

connection defines the connection that will be used. The input must be a scalar uint32 value provided by m4SApiConnect.

result defines if the block will be executed. The input must be a scalar int32 value. The block will not be executed if this value is negative. For negative values the input result is directly fed through to the output result.

bWatchdogOn starts the watchdog on the MLPI target when the signal changes from false to true. The watchdog supervision will be stopped if the input signal changes from true to false. The input must be a scalar boolean value.

Block Outputs

connection contains the connection identifier. The input port connection is fed through to this output. The default value of this port is 0.

result contains the return value of the block. The output is a scalar int32 value. If the output is negative other outputs are invalid. The default value of this output is 0. For details refer to the section Error Identification and Handling in Fundamentals of MLPI Programming.

Parameters and Dialog Box

Sample time (-1 for inherited) specifies the time interval between samples. To inherit the sample time, set this parameter to -1. This block supports discrete sample time, but not continuous sample time.

Characteristics

Direct Feedthrough	Yes
Sample Time	Fixed Step

Example Model

Here you will find instructions to use the examples.

The following example is available in the folder ./mlpi/mlpi4Simulink/blocks:

m4SWatchdog_Sample.mdl

Watchdog Blocks

Description

More Information

m4SWatchdogGetState

m4SWatchdogGetState

Description

Block Inputs

Block Outputs

Parameters and Dialog Box

Characteristics

Example Model

See also