Instruction Manual

266 Language Reference • Reference
Publication 1398-PM601A-EN-P — October 2000
WORDS
SETTASKTIMES
System Task Timing System
Purpose Allows control of timing of system tasks.
Syntax SETTASKTIMES = backgroundtasktime, optermtasktime, i/otasktime
backgroundtask-
time
The new start time in microseconds of the background task. The
background task handles Host command language processing.
The default time for this task is 1649 microseconds. The back-
ground task start time cannot be less than 1649 microseconds.
optermtasktime The new start time in microseconds of the operator terminal task.
The default power up time for this task is 1697 microseconds.
The operator terminal task handles Xkey routine execution, Fkey
routine execution, operator terminal key input, displaying of the
active operator terminal screen, read statements from serial port
#1, and updating Operator Terminal status LED’s.
i/otasktime The new start time in microseconds of the I/O task. The default
power up time for this task is 1840 microseconds. The I/O task
handles updating digital and analog input and output states,
scanned event execution, position interrupt processing, and fault
handling.
Remarks The SetTaskTimes statement can be used to modify default internal task scheduling
times. It is only available in version 3.xx and higher firmware. The majority of appli-
cations will not have to modify background task times. Depending on the require-
ments of the application (main program execution, I/O processing, scanned events,
Xkey routines, operator terminal update rate, host command language processing rate,
etc.), the background task execution times can be tailored to better meet the require-
ments of the application. When specific functions are not required by the application,
they can effectively be turned off to allow increased motion program throughput. The
primary purpose of the SetTaskTimes statement is to allow for maximum motion pro-
gram throughput. An examples of this is reducing background processing when per-
forming a large number of computations within the motion program.
No task start time greater than 1980 microseconds can be specified.
Each task start time must be separated by at least 20 microseconds. In other words,
task times must be programmed to allow each task to execute for at least 20 microsec-
onds.
Note:If any of the task time rules specified above are violated, the system will use
default task start time values.
If the motion program requires the default task times to be in effect, execute SET-
TASKTIMES = 0, 0, 0.
See Also
Example
SETTASKTIMES = 1800, 1820, 1840
SETTASKTIMES = 0, 0, 0