Chapter 5
Generated Code Architecture
5-22
ni.com
Changing %var Values During Startup
A special feature of the Startup allows the value of a %var to be set at
run-time through a Global Variable Block that has the same name as
the %var.
Condition Block
SystemBuild provides three variations of the Condition Block: Default,
No-Default, and Sequential.
Note
AutoCode only supports Standard and Macro Procedures within a Condition Block.
AutoCode does
not
support inline procedures within a Condition Block.
Default Mode
This mode requires that at least one procedure within the Condition Block
will execute. If there are
n
procedures, there are only
n
– 1 conditions and
thus the
n
th procedure will execute if none of the other procedures execute.
No-Default Mode
This mode does not require that at least one procedure will execute. Rather,
if all of the conditions fail, the results from the last time-cycle are used.
AutoCode stores all of the outputs of the last executed procedure within
R_P
to provide this functionality. Type conversions are performed for
non-float data types.
Sequential Mode
This mode independently tests the condition for each of the procedures.
Therefore, all, some, or none of the procedures might execute. If none of
the procedures execute, the outputs are taken from the last time the
procedures executed. Like the no-default mode, the outputs are cached
within the
R_P
and type conversions are performed for non-float data.
BlockScript Block
The BlockScript block lets you create a custom algorithm within the
context of the block in the diagram. This block uses a scripting language
called BlockScript, which AutoCode can translate into C or Ada code.
BlockScript provides a generalized programming capability for defining
SystemBuild blocks for simulation and code generation.