> Pablo Rodriguez <mailto:oinos@gmx.es>
> 2. April 2016 um 20:29
>
> Wolfgang, this was my original sample:
>
> \setuppagenumbering[alternative=doublesided]
> \setupinteractionscreen[option=portrait]
> \starttext
> No duplex printing.
> \page[right]
> In this document.
> \stoptext
>
> The doublesided alternative disables duplex printing.
>
> Hans wrote about portrait and landscape as directives. I guess they
> should be invoked with \enabledirective, but I don’t know how.
No, the option key for \setupinteractionscreen is correct but there are 
a few problems.

1. When you have a doublesided document the “portrait” option loads the 
values
    of the doublesided option.

2. Since you can set only one argument for the option key context has to 
set a values
    for the PDF document which means you can set the zoom value and 
dupley print
    option at the same time. A better solution would be to assign each 
option only a certain
    function and allow one to set 
\setupinteractionscreen[option={doublesided,portrait}].

Wolfgang