Set a list of model variables to be logged to the output window at each communication interval
output <variable name 1> <variable name 2> …
The OUTPUT command is used to specify a list of variables whose values are to be displayed to the output window at each communication interval. This can be useful for monitoring the output of long simulation runs, or as an aid in model debugging. Note that the OUTPUT list is cumulative: that is, the output command adds the specified model variables to a running list of variables to output. In order to clear this list, use the @clear flag.
output t x xd xdd