The current vertical refresh interval of the display system.
<display>
This property reports the vertical refresh interval in milliseconds of the display system.
The following displays the value of refreshinterval in a text stimulus:
<text sometext>
/ items= ("refreshinterval = <% display.refreshinterval %>")
</text>
The following displays the value of refreshinterval in an instruction page:
<page somepage>
refreshinterval = <% display.refreshinterval %>
</page>