by stefan » 22. Dec 2009, 16:07
This is right - you can freeze an input pin in the block description schema to both constants or environment variables. As long as such an input pin is neither connected nor frozen in the step (this is where a block description is used), the pin will get this frozen value as default.
Note, that usually any input pin is sort of optional, because the block description's policy is "AND-CONNECTED" by default. This means, that a step is scheduled as soon as there is data on each of its connected input pins. But in this case there is no data on these "optional" not connected input pins. If you don''t want this, you can set another policy of course.