Signal Composer
Signal Composer builds a calculated parameter from signals already available in the file. Connect source parameters or existing synthetics to mathematical and logical operators, then plot the result as a new synthetic signal.
Unit conversion is a common example. If a vehicle reports miles per gallon and
you want kilometers per litre, take the mpg parameter, multiply it by 0.425144,
and plot the result straight away.
To build one, see Create a synthetic.
Synthetics live in the session that created them. They cannot be saved into a template or carried into another session.
Working in the builder
You can:
- Click and drag anywhere to pan the view
- Right-click in the builder space to add a node, which appears where you clicked
- Click a node to see or edit its properties
- Drag a node to move it
- Select a node, source, or operator and press Backspace on Windows or Delete on a Mac to remove it
Linking nodes
Drag from the output of one node to the input of another. Inputs are the triangles on the left of a node; outputs are the triangles on the right.
What the arrow colors mean
| Color | Meaning |
|---|---|
| Green | The connection is valid |
| Red | A required connection is missing, so the expression cannot resolve |
| Yellow | A boolean value. One yellow output can feed any number of boolean inputs |
| Blue | A numeric output |
The terminus node
The red circle is the terminus node, and every expression needs one. The expression is valid only once the terminus is connected to a node that is not itself in an error state.
The short version: the expression is not finished until the terminus turns from red to green.
Sources
| Source | Description |
|---|---|
| Parameter | A parameter in the current AC-Graph session |
| Synthetic | A synthetic in the current AC-Graph session |
| Numeric | A fixed number, positive or negative |
Operators
Boolean
| Operator | Description |
|---|---|
| And | True when every connected condition is true. For example, vehicle speed above 55 mph and engine speed above 3000 rpm |
| Or | True when at least one connected condition is true |
| Negate | Inverts a boolean. Combine it with And or Or to build a NAND or NOR |
Arithmetic
| Operator | Description |
|---|---|
| Add | Adds values |
| Subtract | Subtracts values |
| Multiply | Multiplies values |
| Divide | Divides values |
| Exponent | Raises a signal to a power |
| Modulus | Returns the remainder of one signal divided by another |
Comparison
Comparison operators output 1 for true and 0 for false.
| Operator | Description |
|---|---|
| Equals | True when the two values match |
| Greater Than | True when the first value exceeds the second |
| Less Than | True when the first value is below the second |
Conditional
| Operator | Description |
|---|---|
| If...Else | Builds conditional logic. It requires you to say, in milliseconds, how long the condition has to hold before it counts |