eeros_architecture:control_system:signals
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eeros_architecture:control_system:signals [2015/10/14 14:12] – graf | eeros_architecture:control_system:signals [2021/03/03 08:29] (current) – [Reading from Unconnected Inputs] ursgraf | ||
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Each element of a signal is characterized by a value, a high precision timestamp, a name and additional properties, depending on the type of signal, which will provide semantic information. Some examples are dimension (e.g. length, mass, current, etc.), SI-unit (e.g. m, m/s, kg, Nm, A, etc.), reference coordinate system or activation state (enabled/ | Each element of a signal is characterized by a value, a high precision timestamp, a name and additional properties, depending on the type of signal, which will provide semantic information. Some examples are dimension (e.g. length, mass, current, etc.), SI-unit (e.g. m, m/s, kg, Nm, A, etc.), reference coordinate system or activation state (enabled/ | ||
- | {{ signaluml.png? | + | [{{ signaluml.png? |
It's important to note that a signal can carry a single value as well as a vector or matrix of values. For this purpose the field //value// is declared as of type T. | It's important to note that a signal can carry a single value as well as a vector or matrix of values. For this purpose the field //value// is declared as of type T. | ||
Signals are used to connect different blocks in the control system and share information between the control system, the sequencer and the safety system. | Signals are used to connect different blocks in the control system and share information between the control system, the sequencer and the safety system. | ||
+ | Supported types for signals are | ||
+ | * Arithmetic (int, double ...) | ||
+ | * Logic (bool) | ||
+ | * Vector (Vector2, Vector3, Vector4) | ||
+ | * Matrix | ||
+ | Each signal can be assigned a name and a unit. All dimensions of a signal share the same name and unit.\\ | ||
- | ===== Using Signals ===== | + | As an example |
- | The example | + | |
<code cpp> | <code cpp> | ||
- | Gain< | + | Sum<2,Vector3> sum; |
- | </ | + | sum.setName("adds feedback" |
+ | sum.getOut().getSignal().setName(" | ||
+ | </ | ||
+ | This is shown in the following diagram: | ||
+ | [{{ sumblock.png? | ||
+ | |||
+ | The functions //getIn()// and // | ||
+ | |||
+ | ===== Timestamp ===== | ||
+ | Every signal carries a timestamp. The timestamp of a signal is usually set in input blocks. Block which read from an external source and deliver this value on a output signal will set its timestamp to the time of the acquisition of the value. \\ | ||
+ | Most blocks will not alter this timestamp. However, blocks which depend on the sampling time such as integrators or differentiators will change the timestamp according to their inner algorithm. | ||
+ | |||
+ | ===== Reading from Unconnected Inputs ===== | ||
+ | If you try to read from an input, which is not connected to an output, a // | ||
- | If a '' | ||
- | <code cpp> | ||
- | Gain< | ||
- | </ | ||
- | In order to access the individual dimensions of a certain signal, use functions like | ||
- | <code cpp> | ||
- | sum.getOut().getValue(); | ||
- | sum.getOut().getValue(0); | ||
- | sum.getOut().getValue(2); | ||
- | sum.getIn(1).getValue(2); | ||
- | </ | ||
eeros_architecture/control_system/signals.1444824744.txt.gz · Last modified: 2015/10/14 14:12 by graf