The lookup table approximates a function defined by a lookup table
Keywords
electrical, unidirectional
Ports
| Name | Type |
|---|---|
| input | Electrical Signal |
| output | Electrical Signal |
Properties
General Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
name Defines the name of the element. |
Lookup Table | - | - |
|
annotate Defines whether or not to display annotations on the schematic editor. |
true | - | [true, false] |
|
enabled Defines whether or not the element is enabled. |
true | - | [true, false] |
|
type Defines the element unique type (read only). |
Lookup Table | - | - |
|
description A brief description of the elements functionality. |
The lookup table approximates a function defined by a lookup table | - | - |
|
prefix Defines the element name prefix. |
TABLE | - | - |
|
model Defines the element model name. |
- | - | - |
|
library Defines the element location or source in the library (custom or design kit). |
- | - | - |
|
local path Defines the local path or working folder $LOCAL for the element. |
- | - | - |
|
url An optional URL address pointing to the element online help. |
- | - | - |
Standard Properties
| Name | Default value | Default unit | Range |
|---|---|---|---|
|
load from file Defines whether or not to load measurements from an input file or to use the currently stored values. |
false | - | [true, false] |
|
filename The file containing user defined input values and correspondent output values. Refer to the Implementation Details section for the format expected. |
- | - | - |
|
table The table allows the user to read or modified input values and correspondent output values. |
<2,2> [0, 1, 0,...] | - | - |
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Implementation Details
An easy understanding of the Lookup Table element is to treat it as a transfer function; an illustration of this element is shown below:
The table, which defines the transfer function, is generally formatted in two columns. For most of the cases when the lookup table is defined in two columns, the first column defines the input and the second column defines the output. A linear interpolation is used to calculate for the output if no direct map if found in the table. Since the 2018b release, the Lookup Table element starts to support multiple input ports. The file that defines in \(N\) columns will have N-1 input ports and the output signal (defined in the last column) depends on all the input signals (defined in the first \(N-1\) columns).
A simple example is in the file lookup_table_example.icp; the schematic design and the table are shown below:
The input and output signals are measured by "OSC_1" and "OSC_2", respectively, and the waveforms are shown below. The relationship between the output and the input are as shown in the table above and it is a broad square effect.