CommandID variable：

The status of many motion commands can be tracked using the unique, project-wide CommandId.

If you enter the name of a variable of data type CommandIdType, you can track the command status with this variable. The variables of this data type that were declared previously in the MCC source file or MCC chart are available for selection.

When the Assign value check box is selected, a unique project-wide CommandId is automatically generated, stored in the variables, and transferred to the command.

You can use the stored CommandId to track the command status until the command has been completed properly or has been aborted.

When the Assign value check box is cleared, only the variable is transferred to the command. You must take steps to ensure that a unique project-wide CommandId is stored in the variable. You obtain the CommandId with the _getCommandId system function.

In addition, you can buffer the CommandId in this case so that it is available even after the command has been completed.

If you leave the field empty, the CommandID is not assigned to any variables; this means that you cannot access the CommandID (default).

When the field is empty, the Assign value check box must be selected.

请帮忙解释一下。