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K
Karnaugh method, 121
Keyboard contacts, 205
L
Ladder Diagram (LD) language, 273–274, 302
number of LAD instructions per rung, 296, 296f
ON-delay timer instruction, 317–318, 317f
parallel or serial execution of instructions, 292–294,
293f–294f, 294t
programming in, 306–308, 307f–308f
Language of logic elements/function block diagram
(FBD), 198, 198f
Latching relays, 30–31
Latch of machines (chain latch), 93, 94f
Latch principle, 79–81
Lathe, defined, 148
Layout for separating objects, PLC programming in,
338–339, 338f
LD language, see Ladder Diagram (LD) language
Lead screw, setup, 8
Lead screw moving worktable, 146–148
Lenz’s law, 21
Level control, pump operation based on, 100
Level controllers, 52–53
Level switches, 52–57
capacitive, 53–54
electronic, for conductive liquids, 52–53
float, 56
optical, 57
radar-type, 55
ultrasonic, 54–55
Life expectancy, electrical/mechanical, 27–28
Light emitting diode (LED), 206
Lightning protection
internal, 253
PLC installation and, 252–253, 254f–255f
Light objects
simple robotic station for receiving and stacking,
395–396, 396f
stacking machine of, 394–395, 395f
Limit switches, 50–52, 205
Liquid(s)
conductive, electronic level switches for, 52–53
flow switches, paddle-type, 57, 58f
Load
defined, 26
monitoring, 70
Load (L) and transfer (T) instructions, PLC
programming, 290
Local and peripheral I/O system, PLCs, 234–236,
234f–236f
of industrial production application, 238–239,
238t
Locked rotor current (LRC), 22–23
Locked rotor torque (LRT), 22
Logical design, of automation circuits, 117–155
applications, 145–155
bidirectional lead screw movable worktable with
two speeds, 146–148
operation of n machines with pause under specific
conditions, 151–155
palindromic movement of worktable with
memory, 148–150
Boolean logic components, 118–121
overview, 117
postulates and theorems of Boolean algebra,
120–121
state diagrams, 121–145
classical, 121–124
components’ state diagram method, 135–137
design methodology, 121
discrete successive signal, step-by-step transition
due to, 128–133
Index
◾
433
examples, 122–128, 129–133, 133–135,
138–142, 143–145
minimum realizations and, 137–142
with sensors, 124–128
sequential automation systems, 142–145
START/STOP operation of motor, 122–124
with time relays, 133–135
Logic coils, 308–310, 309f
M
Machine operation
automatic/manual control, 88–89
control from multiple positions, 107, 108f
control panel for operating n machines, 91
periodic, with two time constants, 88
by pushbuttons and sensor, 124–126
starting delay, 84–86
stopping delay, 87
two machines
common automatic command/separate manual
commands, 90
common manual command/separate automatic
commands, 89–90
two/more points, 90–91
Machine(s)
canceling ability, 98–100
integrated, 1
for chocolate production, 5
defined, 1
operations, 4–6
Magnetic coupling, interference and, 248, 249f
Magnetic latching relays, 30–31
Magnetic proximity switches, 40, 44–45, 46f
Magnetoresistive proximity switch, 45–46
Magnet–reed relay float level switch, 56
Main circuits, 10–11
Manual actuation, of valve, 168, 170, 172f
Manually operated control devices, 5f
Master/Slave protocol, 360, 360f
Mathematical operations, PLC programming using,
327–329, 328f
Mechanical actuation, of valve, 170, 172f
Mechanical latch, 91–94
motor operation with power supply from two
different networks, 94
overview, 91–93
sequential start—latch of machines (chain latch),
93, 94f
Mechanical latching relays, 30
Mechanical life expectancy, 27–28
Memory, PLCs, 231–232
EEPROM, 232
EPROM, 231
RAM, 231
ROM, 231
Memory organization, PLC, 227–231, 228f, 230f
Memory units, PLC, 195
Metallic environment affects, proximity switches, 44,
45f
Metallic objects, chemical cleaning process of, 392–393,
393f
Metal plate rolling mill machine, 402–403, 403f
Meters, hour, 72–73
Micro-electro-mechanical systems (MEMS), 19, 24
Microprocessors, 193; see also Central processing unit
(CPU), PLC
CPU, PLC, 225–226, 227f
address bus, 226, 226f
components, 226–227, 227f
data bus, 226, 226f
Milk tanks, automated filling of, 389–390
Milling machine tool, 138–142
Minimum realizations, state diagrams and, 137–142
Mixed AND and OR logic, 307, 308f
Modular construction, PLC, 200–202, 201f–202f
digital output module of, 203f
Monitoring
load, 70
network, 70
relays, three-phase, 69–70
Motorized timers, 66–67
Motor(s)
AC, 20–23
automation circuits for, 95–97
inversion in rotation, 95, 96f
star-delta (Y-
∆
) start, 96, 97f
types, 97
DC, 20–23
electric, 20–23
multi-state electric, 4, 4f
operation, with thermal overload protection, 82–83
operation with power supply from two different
networks, 94
servomotors, 22
START/STOP operation of, 122–124
stepper, 22, 23
types, 3, 4
Movable worktable
bidirectional lead screw, with two speeds, 146–148
with memory, palindromic movement, 148–150
Multi-conveyor assembly station, automation, 136–137
Multi-network communication structure, 365
Multiple bottle packing station, 404–405, 405f
Multiple positions, machine operation control from, 107,
108f
Multi-state electric motors, 4, 4f
Mutual exclusion, 93, 125
N
National Electrical Manufacturers Association (NEMA),
243
Negative numbers, 411–413, 412f
434
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