Steps in ST
Syntax |
---|
|
Meaning |
---|
a →step within the →SFC network, One or several actions can be associated to the step: See "Evaluating the ST-code including the SFC networks" for information on when a step or initial step is active or inactive and the results of this. The usage of the step is only possible within the current POU. |
Example |
---|
|
Using step flag and step times
It is possible to use the following properties of a step in the current POU. This usage is similar to the usage of a →constant variable.
(The following descriptions are valid for a step with the name name_1
.)
-
Step flag: The active or inactive state of a step can be represented by the logic value of a Boolean structure element
name_1.X
. If the step is active,X
has the valueTRUE
(or an equivalent). In case of an inactive step,X
has the valueFALSE
(or an equivalent). An example for the usage of the step flag is to check the state of one SFC network within a different SFC network. -
Step time: The time elapsed since the initiation of a step can be represented by a structure element
name_1.T
of data typeTIME
: When the step is activated, the value forname_1.T
is reset tot#0s
. When the step is deactivated, the value forname_1.T
remains at the value it had when the step was deactivated. -
Moment in time of activation: The moment in time when the step has been activated can be represented by a structure element
name_1.S
of data typeTIME
.
Example |
---|
|