plc_tank fill system_itt_dcote
- 1. ITT CET Capstone Project PLC Based Tank Fill Control System Utilizing Single feedback Control Denis P. Cote
- 2. System Overview Features Tank Fill Control System Allen Bradley SLC-500 PLC Single Feedback – Strain Gauge Load Beam Load Cell Signal Conditioning Amplifier Ladder Logic
- 3. Overview Program Operation User setpoint: 5 – 100% via input, System activates via start PB #1, Tank fill valve opens, pump starts Tank fills to setpoint, Pump stops, fill valve closes, Tank drain valve opens after 10 seconds, Tank drains to 5% level, Tank drain valve closes, pump restarts, fill valve opens Tank fills back to initial set point, Process repeats; deactivates via stop PB #2
- 4. System Diagram Mechanical Layout Water Tank TK-1 SV Load Cell Suction SV Fill Valve 1 Supply Valve 2 5% 100% Pump Recirc Valve Pump MOT
- 5. PLC Tank Fill System Diagram Single Loop Control SV SV MOT PLC SLC-5/02 INPUTS OUTPUTS Tank Level Set Point Potentiometer I:2.0 PC Signal Conditioner Sensor O:3/2 I:3.0 O:3/0 O:3/1 Fill Valve 1 Drain Valve 2 Pump MotorTK-1
- 6. Control Device List Allen Bradley SLC-5/02 CPU (Slot 0) Input List Load Cell I:3.0 Setpoint I:2.0 Modules 1746-IN4 Analog Module (Slot 1) 1746-IA8 120VAC Input Module (Slot 2) Output List Pump Motor O:3/0 Fill SV-1 O:3/1 Drain SV-2 O:3/3 Modules 1746-OA8 Relay Output Module (Slot 3)
- 7. Feedback Sensor Cantilever Load Beam Strain Gauges Half Bridge Configuration Applied Load, F (i.e., Tank Weight) Fixed End 9.125” 1” .250” F Tension Compression
- 8. Feedback Circuit Diagram +5VDC Regulator (7805) AB 1746-IN4 Analog In Module INA128 Load Cell Supply Voltage 13-15V -5VDC Regulator (7905) OPA177 +12VDC Regulator (7812) -12VDC Regulator (7912) SLC-500 PLC To Regulators
- 10. Performance Data Load Cell Calibration Calibration Data Measured Values Applied Load Tank Level IA Output SG Output Counts Lbf % V' Vo 0 0 0 0 -32 1 20 0.41 1.8 5878 2 40 0.82 3.59 11776 3 60 1.23 5.38 17646 4 80 1.65 7.17 23474 5 100 2.06 8.97 29380 Load Cell Calibration Curve 0 1 2 3 4 5 6 0 1 2 3 4 5 6 7 8 9 10 Output Volts (V) AppliedLoad(Lbf) Field Calibration 0 - 5 Lbs = 0 - 100% tank capacity Known Weights Applied to Cell
- 11. Set Point Input Potentiometer INA128 Instrumentation Amp IC OPA177 OP Amp IC Strain Bridge Ckt TP1 Output Signal Conditioning Amplifier Circuit Breadboard
- 12. Signal Conditioning Amplifier Field Calibration / Proof of Concept
- 13. Ladder Logic
- 14. Back Up
- 15. Load Cell
- 16. Signal Conditioning Schematic Component List C1,3,5,7,9 220uF 50V electrolytic C2,4,6,8,10 0.1uF 50V ceramic D1 LED - Red Rgauge 1,2 Strain Gauge Micro-Measurements CEA-13-187UW-350 350 ohm +/-0.3%, GF 2.145 R3,4 348 ohm, 1% tol. 1/4 watt metal film R5,10 10K trimmer potentiometer R6 1K 1/4 watt R7 50.2 ohm, 1% tol. precision gain resistor R8 5K trimmer potentiometer set to 2.955K R9 10K 1% tol. 1/4 watt metal film R11 100K 1% tol. 1/4 watt metal film U1 INA128P precision, low power instrumentation amp - Texas Instruments U2 OPA177 precision operational amp - Texas instruments U3,4 LM7805 +5Vdc voltage regulator TO-220 U5 LM7812 +12Vdc voltage regulator TO-220 U6 LM7905 -5Vdc voltage regulator TO-220 U7 LM7912 -12Vdc voltage regulator TO-220