Glossary · Electrical engineering and control panels
Input value
Also known as: Input data, Process input value
German: Eingangswert
In industrial control, an input value is the digital value that a controller or function receives from an input signal after conversion, scaling and filtering, for example a raw count, a Boolean state or a value in an engineering unit.
- Control panels
In one sentence
An input value is the digital value a controller receives from an input signal after conversion, scaling and filtering.
Example
The analog input delivers a raw value of 13,824, which the program scales to the input value 5.0 bar for the pressure controller.
How it applies
- Engineering: Define where scaling and filtering happen and use the scaled value consistently. Input values should carry status information (valid, wire break, substitute value) so logic can react to bad data.
- Operation: A frozen or substitute input value looks normal on the HMI unless its status is shown; this is a form of Stale data.
- Documentation: Specify raw range, scaled range, unit, filter and status handling for each value in the I/O list or data dictionary. Function block documentation should state which input values it expects and in which unit.
Input value vs. input signal
The Input signal is the physical quantity at the terminal. The input value is what the software sees. Documentation and error messages should make clear which of the two is meant.