Computer science
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Answer
PLC Programming for Tank Control System
System Description
The system consists of:
- Inlet valve
- Outlet valve
- Mixer motor
- Digital level sensors (to detect whether the tank is full or empty)
Objective
To write PLC programs in the following languages:
- Ladder Diagram (LD)
- Function Block Diagram (FBD)
- Structured Text (ST)
- Sequential Function Chart (SFC)
1. Ladder Diagram (LD)
2. Function Block Diagram (FBD)
Simulation Graphs
- Inlet Valve: Opens when the tank is not full.
- Outlet Valve: Opens when the tank is not empty.
- Mixer Motor: Runs when the tank is full or empty.
Simulation Graphs
- Inlet Valve: Controlled by the "Full" sensor.
- Outlet Valve: Controlled by the "Empty" sensor.
- Mixer Motor: Interlocked with both "Full" and "Empty" sensors.
3. Structured Text (ST)
ST Program
// Structured Text for Tank Control System IF Start THEN IF NOT Full THEN Inlet_V := TRUE; ELSE Inlet_V := FALSE; END_IF; IF NOT Empty THEN Outlet_V := TRUE; ELSE Outlet_V := FALSE; END_IF; IF Full OR Empty THEN Mixer := TRUE; ELSE Mixer := FALSE; END_IF; END_IF;
Simulation Graphs
- Inlet Valve: TRUE when the tank is not full.
- Outlet Valve: TRUE when the tank is not empty.
- Mixer Motor: TRUE when the tank is full or empty.
4. Sequential Function Chart (SFC)
SFC Program
// Sequential Function Chart for Tank Control System Step Init Transition Start Step Fill Action Inlet_V := TRUE; Transition Full Step Drain Action Outlet_V := TRUE; Transition Empty Step Mix Action Mixer := TRUE; Transition Not Empty
Simulation Graphs
- Fill Step: Inlet valve active until the tank is full.
- Drain Step: Outlet valve active until the tank is empty.
- Mix Step: Mixer motor active when the tank is either full or empty.
Simulation Tools
Use an offline simulator such as OpenPLC Editor to test and simulate these programs. Ensure to visualize the input and output signals over time to verify the correct operation of the system.
Project Report
Include the following in the project report for each language:
- The complete program.
- Simulation graphs showing the behavior of inputs and outputs over time.