DVM measurements results are output as scalars, which have a name and a value. The Alias()
function allows you to create a duplicate scalar name with the same scalar value for any
measurement. DVM automatically makes the measurements defined in the DVM Measurements dialog as well as any fixed probes which have probe
measurements. For example, the following scalars are automatically generated for each Bode
plot test objective:
- gain_margin
- phase_margin
- gain_crossover_frequency
Comparing the gain_margin scalar value from one test with the gain_margin in
another test with different operating conditions is difficult since both measurements have
the same name. Using the Alias() function to rename the scalar to reflect unique operating
conditions can help with this comparison.
Alias() Syntax
Single Step Alias Syntax
The single step Alias() function has the following syntax with the arguments
described in the table below:
Alias(scalar_name, new_scalar_name)
| Argument |
Description |
| scalar_name |
Default name for the
scalar. |
| new_scalar_name |
Name as you want it to
appear in the report. |
Note: The value of new_scalar_name is identical to the value of
scalar_name. If the scalar you attempt to rename is not generated for this
test, the Alias() testplan entry is ignored.
Important: Scalar names with spaces will produce errors when used with the
Alias() function. The best solution is to create unique scalar names without
spaces.
For more information on the Alias() function, see 6.6.1 Creating Scalar Aliases in the DVM
tutorial.
Multi-Step Alias Syntax
When using the Multi-Step Analysis, parameters are stepped over a
range of values during a single test. The single step alias syntax will no longer
work for aliasing the scalar values, as all scalar names generated in all simulation
steps will have the same aliased name.
To overcome this, a new aliasing scheme using a template system was added to DVM in
revision 8.00f. If you would like to use this system, make sure your SIMetrix/SIMPLIS version is up to date. You can check your current version with the menu, and check for updates with the menu.
The template syntax is extremely simple, using the stepped variable names enclosed in
"%" signs to create unique scalar names. Here are two examples which describe the
contemplating system:
Single Parameter Step
In this example, a single
parameter representing the input voltage to the power supply,
VIN, is
stepped over 3 values,
360,
380, and
400 volts using an
analysis testplan entry:
Multi-Step( VIN , LIST , 360 , 380 , 400 ). When
the scalar alias is created, the
%VIN% in the
new_scalar_name will
be replaced with the stepped VIN value. For the following scalar alias:
Alias(AVG(VLOAD), AVG(VLOAD_%VIN%_V))
, three scalars will
be created with names:
- AVG(VLOAD_360_V)
- AVG(VLOAD_380_V)
- AVG(VLOAD_400_V)
You can then use these aliased scalar names with the
CreateXYScalarPlot() function to create XY plots at the three input
voltages.
Multiple Parameter Step
In this example, in
addition the input voltage parameter, a parameter
ILOAD is stepped over a
range of values :
0.5,
1.0,
1.5,
2.0 using the
testplan entry:
Multi-Step( ILOAD , LIN , 4 , 0.5 ,2.0 ). Because there are
two variable stepped, this is a nested or multiple parameter step. The total
number of steps will be 3*4 or, 12 total simulation steps. A few example Alias
functions and the created scalar aliases created are shown below.
- Using the same Alias() function as in the single step example, the same
three scalar aliases will be
created:
Alias(AVG(VLOAD), AVG(VLOAD_%VIN%_V))
Creates
these three scalars:
- AVG(VLOAD_360_V)
- AVG(VLOAD_380_V)
- AVG(VLOAD_400_V)
- You can use the ILOAD stepped parameter value and four scalar aliases will
be created, one for each ILOAD stepped
value.
Alias(AVG(VLOAD), AVG(VLOAD_%ILOAD%_A))
Creates
these four scalars:
- AVG(VLOAD_500m_A)
- AVG(VLOAD_1_A)
- AVG(VLOAD_1.5_A)
- AVG(VLOAD_2_A)
Note: The scalar aliases in this case will have the stepped parameter
value converted to a string and represented in engineering notation.
Thus, 0.5 A becomes 500mA, and 2.0 becomes 2.
- Finally, you can use both stepped parameter names in the Alias function and
each parameter name will be replaced with the stepped parameter value. A
scalar alias will be created for each of the 12 simulation
steps.
Alias(AVG(VLOAD), AVG(VLOAD_%VIN%_V_%ILOAD%_A))
Creates
these 12 scalars:
- AVG(VLOAD_360_V_500m_A)
- AVG(VLOAD_360_V_1_A)
- AVG(VLOAD_360_V_1.5_A)
- AVG(VLOAD_360_V_2_A)
- AVG(VLOAD_380_V_500m_A)
- AVG(VLOAD_380_V_1_A)
- AVG(VLOAD_380_V_1.5_A)
- AVG(VLOAD_380_V_2_A)
- AVG(VLOAD_400_V_500m_A)
- AVG(VLOAD_400_V_1_A)
- AVG(VLOAD_400_V_1.5_A)
- AVG(VLOAD_400_V_2_A)
You can then use these aliased scalar names with the
CreateXYScalarPlot() function to create XY plots at the three input
voltages.