This actor sends spec commands into spec. These can either be individual commands, the result of each of which is recorded in a variable and passed on or a single macro file, which does not record output other than in the log file. All commands sent to spec are wrapped in an eval(' ') statement which means they can be typed in to the user interface the same as if entering commands directly into spec. If using the macro file option, you can right click on the actor and open an substitution editor for the maco. This allows upstream variables to be inserted to the macro by highlighting and double clicking the variable on the left. This actor requires tango servers to work and requires the correct tango client settings under 'Window->Prefrences->Data Analysis->Tango'.