Rockwell Automation Logix5000 Controllers Tasks, Programs, and Routines Programming Manual - Manual (Page 68)

Chapter 2 Manage event tasks
Programmatically configure a timeout
To programmatically configure a timeout, use a Get System Value (GSV)
instruction to access the attributes of the task. The following table lists the status
attribute for the TASK object.
Attribute Data Type Instruction Description
Rate DINT GSV
SSV If the task type is Then the Rate attribute specifies the
Periodic Period for the task. Time is in microseconds.
Event The timeout value for the task. Time is in microseconds.
EnableTimeOut DINT GSV
SSV Enables or disables the timeout Function of an event task.
To Set the attribute to
Disable the timeout function 0 (default)
Enable the timeout function 1 (or any non-zero value)
Example To make sure that a timeout value is always defined and enabled for an event task, the logic configures the timeout when the controller enters Run mode.
If S:FS = 1 (first scan) then set the timeout value for Task_2 and enable the timeout function.
1.
The first MOV instruction sets Task_2_Timeout = 10000000 µs (DINT value). Then the SSV instruction sets the Rate attribute for Task_2 =
Task_2_Timeout. This configures the timeout value for the task.
2. The second MOV instruction sets One = 1 (DINT value). Then the SSV instruction sets the EnableTimeout attribute for Task_2 = One. This enables the
timeout function for the task.
Programmatically determine if a timeout occurs
To determine if an event task ran due to a timeout, use a Get System Value (GSV)
instruction to monitor the Status attribute of the task. The following table lists the
Status attribute for the TASK object.
68 Rockwell Automation Publication 1756-PM005-EN-P - October 2014