After each simulation run finishes, SIMPLIS generates a file called
the initial condition file. This file contains a sequence of SIMPLIS netlist
commands that initializes a circuit to the state achieved at the end of
the run. This allows a new run to continue from where a previous run completed.
Note: SIMPLIS creates
this file for every run, including aborted runs.
The initial conditions file is, therefore, volatile and is overwritten
during each simulation run. The file has the same name as the schematic
with the extension .deck.init, and is
stored in the SIMPLIS_Data directory.
The initial condition file can be applied by including it in the netlist
for a new run; in some instances, this may be the most convenient method.
However, it is also possible to annotate the schematic with the initial
condition information. This has some advantages:
- The initial conditions back annotated to top-level capacitors
and inductors will also be recognised in SIMetrix simulation mode.
- Back annotated initial conditions are attached to schematic
instances and will be faithfully reproduced if, for example, a schematic
block is copied and pasted to another schematic
How to Back Annotate a Schematic
To back annotate a schematic, select
from the menu bar. You will
notice a second or two of activity in the schematic and then the operation
does not distinguish between initial conditions that are back-annotated
and initial conditions that are applied manually. After running the back-annotation
algorithm, you will not be able to restore the initial condition value
to those set previously. You can, however, use Undo in the normal way
to reverse the back-annotation operation with a single Undo operation.
Disable/Enable Initial Conditions
To disable all initial conditions defined at the top level (not just
ones that are back-annotated), select
from the menu bar.
To re-enable initial conditions, select
from the menu bar.
In order to apply back-annotation in a generic fashion, SIMetrix needs to modify the
SIMPLIS_TEMPLATE property, but cannot do so if it protected, hence the following error
message, which means that the SIMPLIS_TEMPLATE property is protected for the instances
"The following instances have initial condition
values but do not support back annotation."
You shouldn’t get this error with standard symbols from the SIMetrix
libraries, but you may get it with your own symbols. To fix the problem,
right click on the symbol, select Edit/Add
Properties from the pop-up menu, and then remove the property from
Editing Back-annotated Initial Conditions
Changing the value of an back-annotated initial condition depends on
- If the device is a capacitor or inductor or other devices that
has a user-editable initial condition, use the standard method: select
the symbol and press the F7 key or choose Edit
Part... from the pop-up menu.
- For devices such as subcircuit models and hierarchical blocks,
which have no user-editable initial conditions, select the symbol
and choose Edit Additional Parameters
from the pop-up menu.