Overview sequence controls
Time-controlled process: The next step in the process is active after a certain time passed. Example: The individual words are highlighted one after the other in a certain order:
Sensor-controlled sequence control: Here, the sequence control moves to the next step as soon as, for example, the end position of a cylinder is reached, the setpoint speed of a motor is reached, a certain key is pressed, etc. Since these sensor-controlled sequence controls are mainly used in automation technology, we will discuss them in more detail below.
How the workflow can be described by a Sequential Function Chart (SFC):
The Sequential Function Chart (SFC) is a graphical representation to illustrate the workflow of a machine or facility. The system starts from the basic step and moves to the next step when the transition conditions are fulfilled. Mostly this is the request of the basic position and a start signal. Each step normally includes a command output. The control signal to the actuator can be a short pulse, time-limited, time-delayed and storing.