The shortcut output workflow component, To printer enables you to print out the current printable payload in the workflow onto a selected printer.
If you simply want to merge and print, then you should consider the Print component.
Before calling this component you need to make sure:
1.That the payload of the workflow contains one of the printable formats.
2.That a printer has previously been selected e.g. with the Set printer component.
The To printer component has no parameters.
An example of how this can be used is found here. The example use a PCL file, but the principle is the same for any other printable formats.