Defining Your Own Transform
If your sensor is not listed in the Transform Selector window, or you must account for a signal/noise offset, you can define your own transform.
| 1. | In the Transform Selector window, select a sensor that is similar to the sensor you wish to add. |
| 2. | Click the  button to copy the selected sensor's parameters into the fields at the bottom of the window. (This should give you a starting point close to the sensor you want to add.) |
| 3. | Click the Parameter link. The Parameter Selector window appears. |
| 4. | Double-click on the parameter that you wish map your sensor output to. |
NOTE: The transform will convert the input source into an output of the type of the parameter you selected. When adding channels that use this transform to your layout displays, you simply add the parameter you specified here.
| 5. | In the dropdown to the right of the Parameter link, select the units for the output parameter. |
| 6. | Use the Function fields to specify how the range of values output by the connected sensor should be transformed into the range of values for the selected parameter. See Defining the Function for more information. |
| 7. | Enter a Description for this transform. |
| 8. | Click OK. |
The user transform values you input will be stored with the channel, and will be saved any time you save your channel config.
Defining the Function
The Function fields define how the numerical values associated with the input are converted to their corresponding output values. In the sample screen above, the function is converting values in the range 0-5 (volts) to values in the range 0.62-1.10 (Lambda).
To define the function, you just need two known input values and their corresponding output values. Consult the documentation for the device whose output you are transforming.
Once you have these values, the number to put in the first box can be calculated with the following formula:
(Input2 - Input1) / (Output2 - Output1)
If we used the max and min values from the example above, you would get:
(5 - 0 volts) / (1.10 - 0.62 lambda) = 10.41666
To determine the value of the second box, you simply plug either of the two known input and output pairs into the resulting equation and solve for the missing value.
In our example, if you insert the 0 volt input and it corresponding output value, you get:
0/10.4166 + X = 0.62.
So, X = 0.62.
