Binary Logic Systems in Documentation

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Binary 
Logic
 
Systems
Chapter 
06 – Binary Logic 
Systems
EMEC125
Why Binary Logic
 
Systems?
Documents need 
to 
be 
understood 
by people with 
very different
backgrounds. 
People 
who could need 
the documentation
 
are:
Management
Process
 
Designers
Operations
 
Staffs
M
a
in
t
e
n
a
nce
 
T
e
chnici
a
ns
Electrical 
and 
Control 
System
 
Professionals
Logic 
Device
 
Programmers
Supervisory Control 
and 
Data Acquisition (SCADA) 
System
 
Configurators
Binary Logic
 
Diagrams
ISA-5.2-1976 (R1992) Binary Logic
Diagrams 
for 
Process 
Operations 
and
Scientific Apparatus Makers 
Association
(SAMA) PMC 22.1 Functional
Diagramming of 
Instrument 
and 
Control
Systems. 
Both address binary logic
diagrams.
Elements of these 
standard are 
now
included in
 
ANSI/ISA-5.1
1
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Terms 
You 
Should 
Know Before 
Proceeding
Discrete
 
Control
“On/off control. 
One of the two output 
values is 
equal to 
zero.” 
(International
Society
 
of
 
Automation,
 
2003,
 
p.
 
150)
A 
better definition 
would 
be: 
A signal that 
is either fully 
ON or 
fully 
OFF with
no 
values
 
in-between.
Binary
“1. A 
term 
applied to a signal or 
device 
that has only two 
discrete 
positions or
states. 
When 
used 
in 
its simplest form, 
as in “binary signal” (as opposed to
“analog 
signal”), 
the 
term denotes 
an “on-off” or “high-low” 
state, 
that 
is, 
one
that does not 
represent 
continuously 
varying 
quantities. [ANSI-ISA-5.1-1984
(R1992)].”
 
(International
 
Society
 
of
 
Automation,
 
2003,
 
p.
 
49).
 
                                                                                                                                                                                                                                                                                                             
 
                                                                                                                                                                                                                                                                                                             
 
                                                                                                                                                                                                                                                                                                             
Terms 
You 
Should 
Know Before 
Proceeding
Analog
“1. 
Having 
the 
form 
of continuously 
variable physical 
quantities, as in data.
Contrast 
with 
digital. 
2. The 
representation 
of numerical quantities by means
of 
physical variables, 
such as 
translation, rotation, voltage 
or 
resistance. 
3. A
waveform is 
analog 
if it is 
continuous and 
varies over 
an 
arbitrary range.
Contrast
 
with
 
digital.”
 
(International
 
Society
 
of
 
Automation,
 
2003,
 
p.
 
21).
Another 
way 
to 
define 
Analog 
is: 
A continually 
varying 
signal that can be 
fully
ON, fully 
OFF or any 
level 
in 
between. (International 
Society of Automation,
2003,
 
p.
 
21).
 
                                                                                                                                                                                                                                                                                                             
 
                                                                                                                                                                                                                                                                                                             
 
                                                                                                                                                                                                                                                                                                             
Terms 
You 
Should 
Know Before 
Proceeding
Process
 
Variable
“1. 
Any variable property 
of a 
process. 
The 
term process variable is used 
in
the 
relevant standard 
to apply to all 
variables 
other than 
instrument 
signals
[ANSI/ISA-5.1-1984 (R1992)]. 
2. In the 
treatment 
of material, any
characteristic 
or measurable 
attribute 
whose 
value 
changes with changes in
prevailing 
conditions. Common 
variables are 
flow, 
level, 
pressure 
and
temperature.” 
(International 
Society of Automation, 2003, p.
 
392).
Control Variable (Controlled Variable)
“1. The 
variable 
that the 
control 
system 
attempts 
to 
keep 
at the 
set 
point
value. 
The 
set 
point may be 
constant 
or 
variable. 
2. The part of a 
process 
to be
controlled 
(flow, 
level, temperature, 
pressure, etc.).” 
(International 
Society of
Automation,
 
2003,
 
p.
 
109).
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Combining Analog and On-Off
 
Control
Combining analog and 
on/off control 
schemes can be defined 
by
using:
Process control
 
descriptions
Instrument
 
diagrams
Function
a
l
 
di
a
g
r
am
s
Electrical 
schematic
 
diagrams
These 
documents 
can be used independently or 
together 
depending
upon 
the 
phase of design, 
construction 
or
 
operation.
Process Control
 
Descriptions
The more complex 
the 
process, 
the 
more 
detail that 
is 
required 
in a
Process 
Control 
Description. The following 
are areas 
to 
be included,
but not limited 
to, 
in a Process
 
Description:
Process
 
Description
Title 
of the
 
system
General
 
description
Form
Control
 
Description
More specific 
data on how the 
system 
will
 
perform
Loop-by-loop
 
descriptions
Format
 
                                                                                                                                                                                                                                                                                                             
The 
Binary Concept 
Multiple
 
Input
This 
two-state 
binary 
concept, 
applied 
to 
gates
, 
can be 
the 
basis 
for
making decisions in ladder
 
logic.
The 
gate 
is a device 
that 
has one or more inputs and one
 
output.
The 
gate 
will 
perform 
a logical decision based on 
the 
status 
of 
its
inputs and 
produce 
a result 
at 
its 
one
 
output.
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Using 
Gates to Make
 
Decisions
The logical 
AND 
gate 
or
 
function.
All
 
inputs
 
must
 
be
 
true
 
to
 
obtain
 
an
 
output.
G
a
t
e
Air
 C
o
nditi
o
ner
Switch
   
 
 
AN
D
Bl
o
w
e
r
 
Swi
tch
C
o
ld
 
Air
The automotive air 
conditioning 
to work,
the Air Conditioner must be turned on and
the Blower must be turned
 on.
Using 
Gates to Make
 
Decisions
The logical OR 
gate 
or
 
function.
Any
 
one
 
input
 
must 
be
 
true
 
to
 
obtain
 
an
 
output.
Passenger
D
oo
r
 
Swi
tch
    
 
 
O
R
   
 
 
G
a
t
e
D
r
iver
 
D
oo
r
Switch
D
o
me 
Li
g
ht
The automotive dome 
light 
will be on when
the passenger 
door 
OR the driver 
door or
both 
door 
switch(s) is
 
activated.
The 
AND
 
Function
The AND 
function has two or more
inputs 
and one output. 
The input
signals are labeled 
A, 
B, 
C, 
etc. 
and
the 
output signal is labeled
 
Y.
A 
binary 
1 
represents 
the
 
presence
of 
a 
voltage (signal). 
A 
binary 
0
represents 
the 
absence of voltage
(no signal, 
0 V 
or
 
ground).
Logic functions can 
be
 
represented
using
 
a
 
truth
 
table.
 The
 
truth
 
table
lists all possible 
input 
status
conditions with 
the 
corresponding
output 
status for 
each set of 
input
condition.
Y
A
 
 
Inputs
B
AN
D
             
Output
 
Gate
Two input 
AND
 
gate
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An AND 
Gate
 
Application
An AND 
gate 
functions 
like 
switches in
 
series.
The light will only be ON when switch 
A 
AND 
switch 
B 
are 
both
closed.
AN
D
             
L
T
1
 
ON
 
Gate
PB1
 
=
 
1
PB2
 
=
 
1
 
                                              
The OR
 
Function
The OR 
function has two or more
inputs 
and one output. 
The input
signals are labeled 
A, 
B, 
C, 
etc. 
and
the 
output signal is labeled
 
Y.
A 
binary 
1 
represents 
the
 
presence
of 
a 
voltage (signal). 
A 
binary 
0
represents 
the 
absence of voltage
(no signal, 
0 V 
or
 
ground).
Logic functions can 
be
 
represented
using
 
a
 
truth
 
table.
 The
 
truth
 
table
lists all possible 
input 
status
conditions with 
the 
corresponding
output 
status for 
each set of 
input
condition.
A
B
Y
Inputs
O
R
        
Output
Gate
Two input OR
 
gate
An 
OR 
Gate
 
Application
G
a
t
e
PB3
 
=
 
1
PB4
 
=
 
0
An 
OR 
gate 
functions 
like 
switches in
 
parallel.
The light will be ON when 
either 
or both switch 
A 
OR 
switch 
B 
are
closed.
    
 
 
O
R
               
L
T
2
 
ON
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The 
NOT 
Function
 
(Inverter)
The NOT function 
gate, 
also
called an 
inverter, 
has one input
and one
 
output.
The NOT 
gate 
functions 
like its
name 
states, 
it 
inverts the 
input
signal
 
status.
If 
the 
input is a 
1 
the 
output is a
0.
If 
the 
input is a 0, 
the 
output is a
1.
     
 
Input
 
A
  
 Input
 
A
(n
o
t
 
A)
 
 
A 
NOT 
Gate
 
Application
The NOT 
gate 
functions 
like 
a normally closed
 
switch.
The light will be ON if 
the 
switch is 
NOT 
being 
activated 
and OFF
when 
the 
switch 
IS 
being
 
activated.
Input
 
Input
PB
5
 
PB5
(not
 
PB5)
The NAND
 
Function
 
                                                                                                                                                                                                                                                                                                             
The 
NAND 
gate 
functions 
like 
an
AND 
gate 
with an INVERTER on
its
 
output.
The only time 
that the 
output 
of
a 
NAND 
gate 
is a 
0 
is when all
the 
inputs 
are 
a binary
 
1.
NA
ND
                                   
PB6
 
PB7
Li
g
ht
 
 
   
 
 
Ga
te
Two input 
NAND
 
gate
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The NOR
 
Function
The 
NOR 
gate 
functions 
like 
an
OR 
gate 
with an INVERTER on 
its
output.
The only time 
that the 
output 
of
a 
NOR 
gate 
is a 
1 
is when all 
the
inputs 
are 
a binary
 
0.
PB8
 
 
PB9
 
N
O
R
 
L
T5
Ga
te
Two input 
NOR
 
gate
 
 
The 
XOR (Exclusive- 
OR)
 
Function
 
                                                                                                                                                                                                                                                                                                             
 
                                                                                                                                                                                                                                                                                                             
The 
XOR 
gate 
has 
two 
inputs and
on
e
 
outp
u
t
.
The output of this 
gate 
is a 
1
when 
the two 
inputs 
are
opposite 
to 
each 
other.
Therefore, 
one input a 
1 
and 
the
other a
 
0.
The output of this 
gate 
is a 
0
when both inputs 
are the 
same,
either 
two 
0’s 
or 
two
 
1’s.
PB10
 
 
PB11
 
XO
R
                              
L
T6
Ga
te
 
 
SOL010
 
 
LS10
 
 
Inputs
LS10A
AN
D
             
Output
 
Gate
Two input 
AND
 
gate
AND 
Gate
 
Circuits
Electromechanical Ladder
 
Diagram
PLC/PAC Ladder
 
Diagram
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So
l011
LS011
 
 
Inputs
LS012
O
R
                
Output
 
Gate
Two input OR
 
gate
OR 
Gate
 
Circuits
Electromechanical Ladder
 
Diagram
PLC/PAC Ladder
 
Diagram
G
a
t
e
 
                
AN
D
                
 Ga
te
LS013
 
O
R
                                                             
L
S
014
 
 
Inputs
L
T
013
Output
CR
Combinations of
 
Gates
Electromechanical Ladder
 
Diagram
PLC/PAC Ladder
 
Diagram
O
R
G
ate
LS015
 
 
LS016
 
 
 
Inputs
AN
D
 
LT016
Gate
Output
CR01
 
O
R
C
R0
2
 
  
 
 
G
ate
Combination of
 
Gates
Electromechanical Ladder
 
Diagram
PLC/PAC Ladder
 
Diagram
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A
N
D
G
a
t
e
OR
G
a
t
e
AH017
LS017
 
 
LS031
 
 
Inputs
O
utput
LS018
 
 
Combination of
 
Gates
Electromechanical Ladder
 
Diagram
PLC/PAC Ladder
 
Diagram
A
N
D
G
a
t
e
OR
G
a
t
e
A
N
D
G
a
t
e
Output
L
T
019
PB019
 
 
PB020
 
 
Inputs
PB021
 
 
PB022
 
Combination of
 
Gates
Electromechanical Ladder
 
Diagram
PLC/PAC Ladder
 
Diagram
Why 
is 
this
instruction
programmed
 
open?
 
 
 
AN
D
                            
G
a
t
e
C
R6
LS
021
Inputs
S
O
L
021
Output
C
R6
Combination of
 
Gates
Electromechanical Ladder
 
Diagram
PLC/PAC Ladder
 
Diagram
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Combination of
 
Gates
Electromechanical Ladder
 
Diagram
Why are these
instruction
programmed
 
open?
PLC/PAC Ladder
 
Diagram
This is an XOR
 
circuit
AND
G
a
t
e
OR
G
a
t
e
A
B
Inputs
M
Output
C
 
 
D
Combination of
 
Gates
Electromechanical Ladder
 
Diagram
Draw 
the
 
PLC/PAC
ladder 
diagram
for this
 
logic
 
                                                                                                                                                                                                                                                                                                             
 
                                                                                                                                                                                                                                                                                                             
Control 
Description (From
 
ANSI/ISA-5.1)
Control 
system 
design
 
for:
Small volumes 
for 
long and short periods should allow 
tank to fill to 
a high 
level to
automatically
 
start 
the
 
pump
 
and
 
then
 
to
 
stop
 
the
 
pump
 
at
 
a
 
low 
level.
Large 
volumes 
for 
long periods should allow the pump t run continuously and
maintain 
a 
fixed level 
with a 
level-to-flow 
cascade 
control
 
loop.
Pump 
(run, or operation) control is selected 
by a 
three-position 
Hand-Off-
Auto (H-O-A)
 
selector switch:
Selector switch 
is in “HAND”
 
position.
Selector switch 
is in 
“AUTO”
 
position.
Pump 
should 
be 
stopped at any
 
time:
Automatically 
if 
low 
level 
is
 
exceeded.
By 
operation 
the stop
 
pushbutton.
Switching 
the H-O-A 
selector to 
“OFF”
 
position.
ISA 5.1
 
(2009).pdf
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Instrument
 
Diagram
T-
1
LT
*
02
L
S
L
*0
2
 
*
0
2-B
FT
*
01
FO
P-1
F
I
C
*
01
LIC
*
02
FV
*
01
S
T
O
P
HS
START
HS                    HS                  
 
LSH
*
0
2-A
 
*0
1
 
*
02
H-O-A
(
*)
Functional 
Diagram
 
Symbols
Measuring, 
Input, 
or 
Readout
 
Device
[*] 
= 
Instrument 
Tag
 
Number
Symbols 
from Table 
5.5 
in 
the 
ANSI/ISA-
5.1-2009
 
Standard
(*)
Automatic single-mode
 
controller
(
*)
(
*)
(*)   
 
(*)
Automatic
 
two-mode
 
controller
(*)
Automatic
 
single
 
controller
(
*)
(
*)
(
*)
Manual 
signal
 
processor
Final control
 
element
Control
 
valve
Final control element 
with 
positioner
Control 
valve 
with
 
positioner
Binary Logic 
AND 
& 
OR
 
Gates
A
N
D
A
B
C
A
B
C
Y
Y
A
N
D
OR
OR
A
B
C
A
B
C
Y
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Binary Logic 
NOT 
&
 
Memory
A
N
O
T
A
A
A
N
O
T
M
e
mory
A
B
S
R
C
D
A
B
C
D
1
0
0
0
1
 
 
2
1
0
1
0
3
0
0
1
0
4
0
1
0
1
5
0
0
0
1
6
1
1
1
0
7
0
0
1
0
8
1
1
0
1
M1
M2
LSH*02
 
 
H
S
*
0
2
-
B
L
S
L*
02
M
OL
S
T
O
P
Electrical 
Schematic 
Ladder
 
Diagram
START
H
S*0
2
-
A
 
 
H
O
A
Logic 
Diagram
 
Example
S
T
OP
 
S
T
A
R
T
C
OIL
OVERLOAD
R
E
L
AY 
C
O
N
TA
C
TS
P
u
m
p
S
t
o
p
M
o
t
o
r
 
S
t
a
r
t
er
,
Pump
 
Motor
Overload
M
o
t
o
r
 
S
t
a
r
t
e
r
,
Reset 
Pump
Motor
N
O
T
S
R
N
O
T
A
N
D
P
u
mp
S
t
a
r
t
P
u
m
p
S
t
a
r
t
s
E
l
e
c
t
r
i
c
a
l
L
o
g
i
c
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Function Block 
Diagram 
Allen 
Bradley
 
(FYI)
Function Block 
Diagram 
– Siemens
 
(FYI)
Δ
P     
 
I
Δ
P     
 
I
A        
 
T
A          T        
 
A
T
A
f
(
(
*
x
)
)
FT
*01
LT
*02
FV*01
H
L
LSL
*
02
A
N
D
A
N
D
HS
*02-B
STOP
NOT
A
N
D
A
N
D
 
OR
S      
 
Ro
 
         
 
         
S      
 
Ro
OL
OL  
 
 
 
PUMP
P-1
START
HS
*02-A
A
HS
*01  
 
H-O-A
H       
 
‘1’
 
when
NOT at
Low
 
Level
LSH*02      
at
 
High
Level
This
 
diagram
 
literally
sucks
 
 
SU
 
QU
 
E
Functional
 
Diagram
1
w
h
e
n
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17
P    
 
I
Δ
P    
 
I
A       
 
T
A         T        
 
A
A
Δ          
 
T
f
((*x))
FT
 
LT
*01
 
*02
FV*01
H
 
          
 
 
          
 
L
 
LSL*
02
1
whe
n
NOT 
at
at High
Level
LSH
*02
STOP
Low 
Level                    
HS
*02
-
B
START
HS
*02-A
HS
*01  
 
H-O-A
 
H
A
M2       
 
 
           
 
 
M1            
 
OL
           
 
           
 
     
 
             
 
 
                     
Pump
Functional
 
Diagram
1
when
LabVolt
 
Electrical
Convert Ladder 
to 
Logic
 
Gates
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Convert Ladder 
to 
Logic
 
Gates
Convert this Logic 
to
 
Ladder
Summ
a
ry
 
                                                                                                                                                                                                                                                                                                             
 
                                                                                                                                                                                                                                                                                                             
This 
chapter 
discussed 
discrete control (on/off control) 
in a process
plant.
Logic diagrams will aid in 
the understanding 
of how 
Safety
Instrumented 
Systems 
(SIS)
 
work.
Functional diagram symbols 
were 
discussed along with an example 
of
how 
they are
 
used.
Basic logic 
gates 
have 
been discussed, along with 
the 
symbols used 
to
represent
 
them.
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References
CEmark.com 
& 
European.Authorized-Representative.eu. (1996-2015). 
What 
is CE Marking (CE Mark)?
Retrieved 
June 17, 2015, 
from Welkang 
Tech 
Consulting: 
http://www.ce-marking.org/what-is-ce- 
marking.html
Charlet, 
T. 
(2016, September 8). 
How 
to Replace 
an 
Evaporator Temperature Sensor 
(Switch)
. 
Retrieved
November 22, 2016, 
from 
Your 
Mechanic: https://
www.yourmechanic.com/article/how-to-replace-an- 
evaporator-temperature-sensor-switch-by-timothy-charlet
International 
Society of 
Automation. (2003). 
Automation, Systems, and Instrumentation Dictonary 
(4th 
 
ed.).
Research Triangle Park: 
International 
Society of 
Automation. 
Retrieved from
http://app.knovel.com/hotlink/toc/id:kpASIDE005/automation-systems-instrumentation/automation-
systems-instrumentation
International 
Society of 
Automation. (2009, September 18). ANSI/ISA-5.1-2009 Instrumentation Symbols and
Identification. 
American National Standard
. 
Research Triangle Park, 
North 
Carolina: 
International 
Society  o
f
Aut
o
mati
o
n.
Kirk, 
W. 
F., 
Weedon, 
A. 
T., 
& 
Kirk, 
P. 
(2014). 
Instrumentation and Process Control 
(6th ed.). Orland 
Park, Illinois:
American 
Technical
 
Publishers.
References
Lipták, G. B. 
(Ed.). 
(1995). 
Process 
Measurement 
and Analysis 
(3rd ed.). 
Radnor, Pennsylvania: 
Chilton Book
Company.
McAvinew, 
T., 
& 
Mulley, 
R. (2004). 
Control System 
Documentation 
Applying Symbols and Identification 
(2nd
ed.). 
Research Triangle  Park, 
North 
Carolina, USA: 
International 
Society of 
 
Automation.
Meier, 
F. 
A., 
& 
Meier, 
A. C. (2011). 
Instrumentation and Control Systems 
Documentation 
(2nd ed.). 
Research
Triangle Park, 
North 
Carolina: 
International 
Society of 
 
Automation.
Ruelas, E. (2016, January 6). 
Symptoms 
of 
a Bad 
or 
Failing AC 
Control Switch
. 
Retrieved 
September 8, 2016,  
from
Your 
Mechanic: https://
www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-ac-control- 
 switch
Shutterstock. 
(n.d.). 
Car Air Conditioner
. 
Retrieved 
September 8, 2016, 
from Shutterstock:
https://
www.shutterstock.com/search/car+air+conditioner
Sourceingmap. 
(n.d.). 
Car 
Vehicle 
Interior Door Courtesy Light Switch Button Part
. 
Retrieved 
September 8, 2016,
from 
Amazon.co.uk:
 
https://
www.amazon.co.uk/Vehicle-Interior-Courtesy-Switch-Button/dp/B00B0QLVSS
References
Wu, 
E. (2012, June 18). 
2011 
Chevy Camaro equipped with LED Interior 
Dome 
Lights
. 
Retrieved 
September 8,  2016,
from 
iJDMTOY Blog 
for 
Automotive 
Lighting:  
http://ijdmtoy.com/BLOG/wordpress/2012/06/18/2011-chevy-
camaro-equipped-with-led-interior-dome- 
 lights/
Thomas, E. C. (2015). 
Introduction to Process Technology 
(4th ed.). Boston, MA: 
Cengage 
 
Learning.
16
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Binary logic systems play a crucial role in documentation for individuals with diverse backgrounds such as management, process designers, operations staff, maintenance technicians, and more. These systems, depicted in binary logic diagrams, provide a clear and concise representation for various professionals to comprehend and apply in their respective fields. The integration of binary logic with analog and on-off control further enhances the efficiency and effectiveness of control systems in diverse industrial applications. By combining analog and on-off control schemes and utilizing different types of documentation, including process control descriptions, instrument diagrams, and functional diagrams, a comprehensive understanding and implementation of binary logic systems can be achieved.


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  1. 06/06/2017 Binary LogicSystems Chapter 06 Binary Logic Systems EMEC125 Why Binary Logic Systems? Documents need to be understood by people with very different backgrounds. People who could need the documentation are: Management ProcessDesigners OperationsStaffs Maintenance Technicians Electrical and Control SystemProfessionals Logic DeviceProgrammers Supervisory Control and Data Acquisition (SCADA) System Configurators Binary Logic Diagrams ISA-5.2-1976 (R1992) Binary Logic Diagrams for Process Operations and Scientific Apparatus Makers Association (SAMA) PMC 22.1 Functional Diagramming of Instrument and Control Systems. Both address binary logic diagrams. Elements of these standard are now included inANSI/ISA-5.1 1

  2. 06/06/2017 Terms You Should Know Before Proceeding DiscreteControl On/off control. One of the two output values is equal to zero. (International Society ofAutomation, 2003, p. 150) A better definition would be: A signal that is either fully ON or fully OFF with no valuesin-between. Binary 1. A term applied to a signal or device that has only two discrete positions or states. When used in its simplest form, as in binary signal (as opposed to analog signal ), the term denotes an on-off or high-low state, that is, one that does not represent continuously varying quantities. [ANSI-ISA-5.1-1984 (R1992)]. (InternationalSociety of Automation, 2003, p. 49). Terms You Should Know Before Proceeding Analog 1. Having the form of continuously variable physical quantities, as in data. Contrast with digital. 2. The representation of numerical quantities by means of physical variables, such as translation, rotation, voltage or resistance. 3. A waveform is analog if it is continuous and varies over an arbitrary range. Contrastwith digital. (InternationalSociety of Automation, 2003, p. 21). Another way to define Analog is: A continually varying signal that can be fully ON, fully OFF or any level in between. (International Society of Automation, 2003,p.21). Terms You Should Know Before Proceeding ProcessVariable 1. Any variable property of a process. The term process variable is used in the relevant standard to apply to all variables other than instrument signals [ANSI/ISA-5.1-1984 (R1992)]. 2. In the treatment of material, any characteristic or measurable attribute whose value changes with changes in prevailing conditions. Common variables are flow, level, pressure and temperature. (International Society of Automation, 2003, p.392). Control Variable (Controlled Variable) 1. The variable that the control system attempts to keep at the set point value. The set point may be constant or variable. 2. The part of a process to be controlled (flow, level, temperature, pressure, etc.). (International Society of Automation,2003, p.109). 2

  3. 06/06/2017 Combining Analog and On-Off Control Combining analog and on/off control schemes can be defined by using: Process control descriptions Instrumentdiagrams Functional diagrams Electrical schematicdiagrams These documents can be used independently or together depending upon the phase of design, construction or operation. Process Control Descriptions The more complex the process, the more detail that is required in a Process Control Description. The following are areas to be included, but not limited to,in a ProcessDescription: ProcessDescription Title of thesystem Generaldescription Form ControlDescription More specific data on how the system willperform Loop-by-loopdescriptions Format The Binary Concept Multiple Input This two-state binary concept, applied to gates, can be the basis for making decisions in ladderlogic. The gate is a device that has one or more inputs and one output. The gate will perform a logical decision based on the status of its inputs and produce a result at its one output. 3

  4. 06/06/2017 Using Gates to Make Decisions The logical AND gate orfunction. Allinputs mustbe true to obtain an output. Air Conditioner Switch AND Cold Air Gate Blower Switch The automotive air conditioning to work, the Air Conditioner must be turned on and the Blower must be turned on. Using Gates to Make Decisions The logical OR gate orfunction. Any one input must be true to obtain anoutput. Passenger Door Switch OR Gate Dome Light Driver Door Switch The automotive dome light will be on when the passenger door OR the driver door or both door switch(s) isactivated. The ANDFunction The AND function has two or more inputs and one output. The input signals are labeled A, B, C, etc. and the output signal is labeledY. A binary 1 represents thepresence of a voltage (signal). A binary 0 represents the absence of voltage (no signal, 0 V orground). Logic functions can berepresented using a truth table. The truth table lists all possible input status conditions with the corresponding output status for each set of input condition. AND Gate Output A Y Inputs B Two input ANDgate 4

  5. 06/06/2017 An AND Gate Application An AND gate functions like switches inseries. The light will only be ON when switch A AND switch B are both closed. PB1=1 AND Gate LT1 ON PB2=1 The ORFunction The OR function has two or more inputs and one output. The input signals are labeled A, B, C, etc. and the output signal is labeledY. A binary 1 represents thepresence of a voltage (signal). A binary 0 represents the absence of voltage (no signal, 0 V orground). Logic functions can berepresented using a truth table. The truth table lists all possible input status conditions with the corresponding output status for each set of input condition. OR Gate A Output Y Inputs B Two input ORgate An OR Gate Application An OR gate functions like switches inparallel. The light will be ON when either or both switch A OR switch B are closed. PB3=1 OR LT2 ON PB4=0 Gate 5

  6. 06/06/2017 The NOT Function (Inverter) The NOT function gate, also called an inverter, has one input and oneoutput. The NOT gate functions like its name states, it inverts the input signalstatus. If the input is a 1 the output is a 0. If the input is a 0, the output is a 1. Input Input A A (not A) A NOT Gate Application The NOT gate functions like a normally closedswitch. The light will be ON if the switch is NOT being activated and OFF when the switch IS beingactivated. Input Input PB5 PB5 (notPB5) The NANDFunction NAND Gate PB6 Light The NAND gate functions like an AND gate with an INVERTER on itsoutput. The only time that the output of a NAND gate is a 0 is when all the inputs are a binary1. PB7 Two input NANDgate 6

  7. 06/06/2017 The NORFunction NOR Gate LT5 PB8 The NOR gate functions like an OR gate with an INVERTER on its output. The only time that the output of a NOR gate is a 1 is when all the inputs are a binary0. PB9 Two input NORgate The XOR (Exclusive- OR) Function XOR Gate PB10 LT6 The XOR gate has two inputs and one output. The output of this gate is a 1 when the two inputs are opposite to each other. Therefore, one input a 1 and the other a0. The output of this gate is a 0 when both inputs are the same, either two 0 s or two1 s. PB11 AND Gate Circuits Electromechanical Ladder Diagram PLC/PAC LadderDiagram AND Gate Output LS10 SOL010 Inputs LS10A Two input ANDgate 7

  8. 06/06/2017 OR Gate Circuits Electromechanical Ladder Diagram PLC/PAC LadderDiagram OR Gate Output LS011 Sol011 Inputs LS012 Two input ORgate Combinations of Gates Electromechanical Ladder Diagram PLC/PAC LadderDiagram OR LS013 AND Gate LT013 LS014 Gate Output Inputs CR Combination of Gates Electromechanical Ladder Diagram PLC/PAC LadderDiagram OR Gate LS015 LS016 AND Gate Inputs LT016 Output OR Gate CR01 CR02 8

  9. 06/06/2017 Combination of Gates Electromechanical Ladder Diagram PLC/PAC LadderDiagram AND Gate LS017 LS031 Output OR Gate Inputs AH017 LS018 Combination of Gates Electromechanical Ladder Diagram PLC/PAC LadderDiagram AND Gate PB019 PB020 Output OR Gate LT019 Inputs AND Gate PB021 PB022 Combination of Gates Electromechanical Ladder Diagram PLC/PAC LadderDiagram Why is this instruction programmedopen? CR6 AND Gate CR6 SOL021 Inputs Output LS021 9

  10. 06/06/2017 Combination of Gates Electromechanical Ladder Diagram Why are these instruction programmedopen? PLC/PAC LadderDiagram This is an XORcircuit Combination of Gates Electromechanical Ladder Diagram Draw thePLC/PAC ladder diagram for thislogic OR Gate A B Inputs AND Gate M CD Output Control Description (From ANSI/ISA-5.1) Control system designfor: Small volumes for long and short periods should allow tank to fill to a high level to automaticallystart the pump and then tostop the pump at a low level. Large volumes for long periods should allow the pump t run continuously and maintain a fixed level with a level-to-flow cascade control loop. Pump (run, or operation) control is selected by a three-position Hand-Off- Auto (H-O-A)selector switch: Selector switch is in HAND position. Selector switch is in AUTO position. Pump should be stopped at anytime: Automatically if low level isexceeded. By operation the stoppushbutton. Switching the H-O-A selector to OFF position. ISA 5.1(2009).pdf 10

  11. 06/06/2017 InstrumentDiagram STOP LSL LIC HS *02 *02 *02-B START LT HS HS LSH *02-A *01 *02 *02 T-1 FIC H-O-A *01 FT FV *01 *01 FO P-1 Functional Diagram Symbols Measuring, Input, or Readout Device [*] = Instrument Tag Number Symbols from Table 5.5 in the ANSI/ISA- 5.1-2009Standard (*) (*) Automatic single-modecontroller (*) Automatic two-mode controller (*) (*) (*) Automaticsinglecontroller (*) Manual signalprocessor (*) Final control element Control valve (*) Final control element with positioner Control valve withpositioner (*) Binary Logic AND & OR Gates A B C Y 0 0 0 0 AND 0 0 1 0 A B C A B C A N D 0 1 0 0 Y Y 0 1 1 0 1 0 0 0 1 0 1 0 1 1 0 0 1 1 1 1 A B C Y OR 0 0 0 0 0 0 1 1 A B C A B C 0 1 0 1 Y OR 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 1 11

  12. 06/06/2017 Binary Logic NOT & Memory NOT A A A A A A 0 1 NOT 1 0 A B C D 1 0 0 0 1 Memory 2 1 0 1 0 3 0 0 1 0 4 0 1 0 1 A C S 5 0 0 0 1 B D R 6 1 1 1 0 7 0 0 1 0 8 1 1 0 1 Electrical Schematic Ladder Diagram START HS*02-A M1 STOP H O A M HS*02-B LSL*02 OL M2 LSH*02 Logic Diagram Example Electrical STOP START COIL OVERLOAD RELAY CONTACTS Logic Pump Start A N D Pump Stop Pump Starts NOT Motor Starter, PumpMotor Overload S NOT R Motor Starter, Reset Pump Motor 12

  13. 06/06/2017 Function Block Diagram Allen Bradley (FYI) Function Block Diagram Siemens (FYI) Functional Diagram 1 when LSH*02 at High Level FT *01 LT *02 H A N D S A A Ro HS *01 H-O-A H OL T A N D START A N D P I P I PUMP P-1 OR HS A T A T A *02-A S 1 when NOT at Low Level LSL*02 Ro f (( * x) ) L A N D STOP NOT A N D HS FV*01 This diagram literally sucks SUQUE *02-B OL 13

  14. 06/06/2017 Functional Diagram 1 when at High Level M2 LSH*02 FT *01 LT *02 H A T P I P I A T A T A A LSL*02 HS *01 H-O-A Pump f((* x)) L H FV*01 OL 1 when NOT at STOP Low Level HS *02-B START HS *02-A M1 LabVolt Electrical Convert Ladder to Logic Gates 14

  15. 06/06/2017 Convert Ladder to Logic Gates Convert this Logic toLadder Summary This chapter discussed discrete control (on/off control) in a process plant. Logic diagrams will aid in the understanding of how Safety Instrumented Systems (SIS) work. Functional diagram symbols were discussed along with an example of how they areused. Basic logic gates have been discussed, along with the symbols used to representthem. 15

  16. 06/06/2017 References CEmark.com & European.Authorized-Representative.eu. (1996-2015). What is CE Marking (CE Mark)? Retrieved June 17, 2015, from Welkang Tech Consulting: http://www.ce-marking.org/what-is-ce- marking.html Charlet, T. (2016, September 8). How to Replace an Evaporator Temperature Sensor (Switch). Retrieved November 22, 2016, from Your Mechanic: https://www.yourmechanic.com/article/how-to-replace-an- evaporator-temperature-sensor-switch-by-timothy-charlet International Society of Automation. (2003). Automation, Systems, and Instrumentation Dictonary (4th ed.). Research Triangle Park: International Society of Automation. Retrieved from http://app.knovel.com/hotlink/toc/id:kpASIDE005/automation-systems-instrumentation/automation- systems-instrumentation International Society of Automation. (2009, September 18). ANSI/ISA-5.1-2009 Instrumentation Symbols and Identification. American National Standard. Research Triangle Park, North Carolina: International Society of Automation. Kirk, W. F., Weedon, A. T., & Kirk, P. (2014). Instrumentation and Process Control (6th ed.). Orland Park, Illinois: American Technical Publishers. References Lipt k, G. B. (Ed.). (1995). Process Measurement and Analysis (3rd ed.). Radnor, Pennsylvania: Chilton Book Company. McAvinew, T., & Mulley, R. (2004). Control System Documentation Applying Symbols and Identification (2nd ed.). Research Triangle Park, North Carolina, USA: International Society of Automation. Meier, F. A., & Meier, A. C. (2011). Instrumentation and Control Systems Documentation (2nd ed.). Research Triangle Park, North Carolina: International Society of Automation. Ruelas, E. (2016, January 6). Symptoms of a Bad or Failing AC Control Switch. Retrieved September 8, 2016, from Your Mechanic: https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-ac-control- switch Shutterstock. (n.d.). Car Air Conditioner. Retrieved September 8, 2016, from Shutterstock: https://www.shutterstock.com/search/car+air+conditioner Sourceingmap. (n.d.). Car Vehicle Interior Door Courtesy Light Switch Button Part. Retrieved September 8, 2016, from Amazon.co.uk: https://www.amazon.co.uk/Vehicle-Interior-Courtesy-Switch-Button/dp/B00B0QLVSS References Wu, E. (2012, June 18). 2011 Chevy Camaro equipped with LED Interior Dome Lights. Retrieved September 8, 2016, from iJDMTOY Blog for Automotive Lighting: http://ijdmtoy.com/BLOG/wordpress/2012/06/18/2011-chevy- camaro-equipped-with-led-interior-dome- lights/ Thomas, E. C. (2015). Introduction to Process Technology (4th ed.). Boston, MA: Cengage Learning. 16

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