11Level 4
Batch mixer in SFC
A classic sequence: load ingredient A, then B, mix for 8 seconds and drain. It is written in SFC (steps and transitions chart), the language designed precisely for step-by-step processes.
Open in the simulator
The simulator is designed for computers (screens 1024 px or wider).
Virtual plant
Good batches: 0. Bad batches: 0
Shown at rest. In the simulator the plant moves according to your program's outputs.
Inputs and outputs
| Address | Name | Description |
|---|---|---|
| I0.0 | START | Start batch push button |
| I0.1 | STOP | Stop push button (NC: 1 at rest); prevents starting a batch |
| I0.2 | LEVEL_A | Ingredient A level switch, 40 % (plant) |
| I0.3 | FULL | Tank full switch, 80 % (plant) |
| I0.4 | EMPTY | Tank empty switch (plant) |
| Q0.0 | VALVE_A | Ingredient A valve |
| Q0.1 | VALVE_B | Ingredient B valve |
| Q0.2 | AGITATOR | Agitator motor |
| Q0.3 | DRAIN_VALVE | Drain valve |
| Q0.4 | BATCH_DONE | Batch done light (stays on until the next batch) |
Program
Sequential function chart (SFC)
Step by step
- 1Press ▶ Run (F5). The initial step IDLE (double border) becomes active by itself. Press START: the transition is true because the tank is empty and STOP is at rest.
- 2FILL_A opens VALVE_A (action N: only while the step is active) and turns BATCH_DONE off (R). At 40 %, LEVEL_A makes the transition true and moves on to FILL_B, which fills up to FULL.
- 3MIX turns the agitator on. Its transition uses the step time: MIX.T >= T#8s. Watch the time run inside the active step.
- 4DRAIN opens the outlet and turns BATCH_DONE on with S (it stays on). With the tank empty it returns to IDLE (the arrow → IDLE is a jump). The plant grades each batch: try lowering the mixing time to T#3s and you will get a bad batch.