Name - The name is a derived field from the Step command type, the target Sound Item or Script, and the time control used if any.
(for Play Sound Item steps only)
Override Output Group Index - Overrides the Output Group specified in the Sound Item > Play Modifiers. Set the value to any valid ouput. Ignored if Output Override is not checked. This allows you to create one Sound Item and direct the sound to different Output Groups.
Output Override - When checked, enables the override of Output Group specified in the Sound Item with this Step Output Group Index.
Change Referenced Item > - This button will allow you to change the Command's referenced item. The item type depends on the type of Step (ie Play Sound Item, Run Script, or Start External Program).
Text Variable > - Some Step types allow a text Variable(s). This is only exposed when the step type allows for a variable. (ex. Start External Program, see Figure 2)
Run Script - Spawns New Thread - This is only exposed for Run Script Steps. In most cases, it is best to leave this box unchecked. See the section on Script Threads for more details.
When checked, a Run Script Step will spawn a Script in a new, separate thread. The new thread begins executing immediately and concurrent with the parent script.
If you use this mode, be sure to also set the Automator > Tools > Allow Concurrent Scripts to Run menu item.
When unchecked, the target Script will be started inside the parent Script's thread. It's steps will begin to execute sequentially, suspending the parent script until its steps have finished executing.
Not all of the controls above are available for every type of Step command.
When no time control is enabled, the Step is treated as a simple sequential Step.
A Sound Item already has an Output Group so the Override provides a way to override that value in a Script. So a given Sound Item can be played on multiple devices without having to make multiple copies of the Sound Item.
Enable: Offset Time - Enables use of the Offset Time for this Step.
Offset Time - Sets the Offset Time amount. Once the containing Script starts to run, the Step will fire after the Offset time expires. (1000 milliseconds = 1 second, ex 500ms = 0.5 second)
Clear Time - Button clears the Offset Time to 00:00:00.000. (productivity aid)
Auto Reset - Enables Auto Reset of the Offset Time. Step is automatically reset to fire again each time the Offset time expires. A Script with 'Auto Reset' steps will continue to run until it is stopped (either manually or by a Stop-Script step). In general, Scripts that contain 'Auto Reset' steps should not be set to Repeat. See caution below about Scripts that Repeat.
A Caution about a Repeating Script with Offset Timed Steps
If you Repeat or Loop a Script that only contains ONLY Offset Timed Steps, then make sure you enable Repeat after Offset Time and set the Repeat Offset to an amount of time to allow all steps to execute before repeating the script.
If you Loop such a Script WITHOUT Repeat after Offset Time, it will probably create a Runaway condition which the Automator should detect and abort.
Multiple commands - You can send multiple commands at one time. Each command is separated by a semi-colon (;). This is more efficient (runs faster) than creating multiple Steps.
Example: RunScript 123 ; RunScript 456 ; RunScript 789
Case-Insensitive - The command is case-insensitive; So RunScript, runscript, RUNSCRIPT are all acceptable.
Figure 3 shows the possible IPC Commands you can use for the variable(s).