Ladder Diagram Fundamentals p. 1
Objectives p. 1
Introduction p. 1
Basic Components and Their Symbols p. 2
Fundamentals of Ladder Diagrams p. 13
Machine Control Terminology p. 31
Summary p. 33
The Programmable Logic Controller p. 35
Objectives p. 35
Introduction p. 35
A Brief History p. 36
PLC Configurations p. 37
System Block Diagram p. 42
Update-Solve the Ladder-Update p. 43
Update p. 44
Solve the Ladder p. 45
Summary p. 48
Fundamental PLC Programming p. 50
Objectives p. 50
Introduction p. 50
Physical Components vs. Program Components p. 51
Example Problem--Lighting Control p. 56
Internal Relays p. 58
Disagreement Circuit p. 59
Majority Circuit p. 59
Oscillator p. 62
Holding (also called Sealed, or Latched) Contacts p. 64
Always-ON and Always-OFF Contacts p. 65
Ladder Diagrams Having More Than One Rung p. 67
Summary p. 69
Advanced Programming Techniques p. 72
Objectives p. 72
Introduction p. 72
Ladder Program Execution Sequence p. 73
Flip Flops p. 73
R-S Flip Flop p. 73
One Shot p. 74
D Flip Flop p. 77
T Flip Flop p. 79
J-K Flip Flop p. 81
Counters p. 83
Sequencers p. 85
Timers p. 87
Master Control Relays and Control Zones p. 96
Summary p. 98
Mnemonic Programming Code p. 103
Objectives p. 103
Introduction p. 103
AND Ladder Rung p. 104
Entering Normally Closed Contacts p. 105
OR Ladder Rung p. 106
Simple Branches p. 107
Complex Branches p. 110
Summary p. 112
Wiring Techniques p. 115
Objectives p. 115
Introduction p. 115
PLC Power Connection p. 116
Input Wiring p. 119
Inputs Having a Single Common p. 121
Isolated Inputs p. 124
Output Wiring p. 126
Relay Outputs p. 127
Solid State Outputs p. 131
Summary p. 137
Analog I/O p. 139
Objectives p. 139
Introduction p. 139
Analog (A/D) Input p. 110
Analog (D/A) Output p. 144
Analog Data Handling p. 145
Analog Input Potential Problems p. 146
Summary p. 147
Discrete Position Sensors p. 150
Objectives p. 150
Introduction p. 150
Sensor Output Classification p. 151
Connecting Discrete Sensors to PLC Inputs p. 154
Proximity Sensors p. 156
Inductive Proximity Sensors p. 156
Capacitive Proximity Sensors p. 159
Ultrasonic Proximity Sensors p. 161
Optical Proximity Sensors p. 163
Summary p. 167
Encoders, Transducers, and Advanced Sensors p. 169
Objectives p. 169
Introduction p. 169
Temperature p. 170
Liquid Level p. 175
Force p. 177
Pressure/Vacuum p. 181
Flow p. 186
Inclination p. 192
Acceleration p. 193
Angle Position Sensors p. 194
Linear Displacement p. 204
Summary p. 209
Closed-Loop and PID Control p. 212
Objectives p. 212
Introduction p. 212
Simple Closed-Loop Systems p. 212
Problems with Simple Closed-Loop Systems p. 214
Closed-Loop Systems Using Proportional, Integral, Derivative (PID) p. 218
Derivative Function p. 220
Integral Function p. 225
The PID in Programmable Logic Controllers p. 228
Tuning the PID p. 229
The "Adjust and Observe" Tuning Method p. 231
The Ziegler-Nichols Tuning Method p. 233
Autotuning PID Systems p. 239
Summary p. 240
Motor Controls p. 242
Objectives p. 242
Introduction p. 242
AC Motor Starter p. 243
AC Motor Overload Protection p. 245
Specifying a Motor Starter p. 247
DC Motor Controller p. 248
Variable Speed (Variable Frequency) AC Motor Drive p. 255
Summary p. 258
System Integrity and Safety p. 260
Objectives p. 260
Introduction p. 260
System Integrity p. 260
Equipment Temperature Considerations p. 263
Fail Safe Wiring and Programming p. 264
Safety Interlocks p. 268
Summary p. 272
Logic Symbols p. 274
Industrial Electrical Symbols p. 276
Bibliography p. 281
Glossary p. 283
Index p. 297