Delta RMC151 - Manual (Page 306)

RMC70/150 and RMCTools User Manual
• Apply the changes to the RMC by right-clicking Programming and clicking
Download Programs to Controller.
Assigning User Programs to Tasks
By default, a user program is allowed to run on only one task at a time. This setting is
usually sufficient for most applications. You can change this to specify a certain task that
the user program is allowed to run on, or allow the user program to run on any number of
tasks simultaneously. Restricting the tasks that a program can run on will help detect
program errors and help reduce the maximum programming execution time.
To change this setting, in the Project pane, right-click the user program, choose
Properties, and choose the Tasks page.
Default Axis
Each task has a Default Axis associated with it. The Default Axis is used in a User
Program when a command’s Commanded Axes field is set to “Default Axis” or when an
expression in a user program contains an axis register, but does not specify the axis (for
example, _Axis[].StatusBits.InPos).
When a task is started using a Start Task (90) command, the Default Axis for the task will
be automatically set to the axis that received the Start Task command.
When a task is started from the Program Triggers, the Default Axis for the task is left
unchanged. On power-up, the Default Axis for task #n is Axis n, up to the number of
available axes. For any additional tasks, the Default Axis is Axis 0 on power-up. However,
the Default Axis for a task can change through Start Task commands (see above) or the
Current Axis register (see below).
The Default Axis for a task can be changed at any time by changing the Current Axis
register for the task (see _CurAxis below). For example, to restore the Default Axis for a
task to its power-on default axes on an 8-axis controller, you could use the following
expression:
_CurAxis := SEL(_CurTask < 8, _CurTask, 0);
The Default Axis is typically used only in advanced applications and is not recommended
for new users.
Why Bother?
Consider a multi-axis application where each axis runs the exact same sequence. Instead
of creating one user program for each axis, you can create a single user program that
issues commands to the Default Axis, and does not specify an axis in the link condition.
Simply issue the Start Task commands to each axis. The user program can run
independently on separate tasks simultaneously.
Using the Task Tags in Expressions
This section is for advanced users only.
The _Task[] tag has several members that can be used to manage tasks with
expressions. The "_Task[]" tag can be used without any value in the brackets to
reference the task that is running that user program.
_Task[].CurAxis
_Task[].CurProg
_Task[].CurStep
_Task[].Status
_Task[].CurProgStep
Using the Default Axis
In expressions in the user programs, the "_Axis[]" tag can be used without any value in
the brackets to reference the default axis.
Changing the Default Axis
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