1. Programmable Logic Controller
Boolean Algebra

2. Programming Restrictions
PLC does not allow for programming vertical contacts.
PLC does not allow logic continuity (power flow) from right to left. A B C D E F A B C D E F G

3. A B F D C C E A B C G D E D E F E F D B C

4. Self Latching Circuit A B F F

5. Boolean Algebra
The purpose of Boolean algebra is to provide a simple way of writing complicated combinations of logic statements

6. Gate Boolean EquationsY
AND
Y = A B
Gate
Boolean Equation OR A B Y
Y = A + B
NOT A Y
Y = A

20. 1. Which gate logic shown represents the Boolean
equation: ( A + B ) C = Y
(a)
(b)
(c)
(d)

21. 2. The correct Boolean equation for the combination logic gate circuit shown is:
a. Y = A B C D c. Y = ( A + B ) ( C + D )
b. Y = ( AB ) + ( CD ) d. Y = ( AB ) + ( CD )

22. 3. The correct Boolean equation for the combination logic gate circuit shown is:
a. Y = ( A + B + C ) D c. Y = ( AB + C ) D
b. Y = ( A + B ) ( C + D ) d. Y = ( ABC ) D

23. 4. The correct Boolean equation for the combination logic gate circuit shown is:
a. Y = A B C c. Y = A + B + C
b. Y = ( A B ) C d. Y = ( AB ) + ( BC )

24. 5. The correct Boolean equation for the ladder
logic program shown is:
a. Y = (A B) + (CD) c. Y = A + B + C + D
b. Y = (A+B ) (C+D) d. Y = ABCD

25. 6. The correct Boolean equation for the ladder
logic program shown is:
a. Y = (A B) + (CD) c. Y = A + B + C + D
b. Y = AB (C+D) d. Y = ABC + D

26. 7. If you want to know when matching bits in two different words are both "on", you would use the _____ logic instruction.
a. AND c. XOR
b. OR d. NOT
8. If you want to reverse the state of bits in a word, you would use the ______ logic instruction.
a. AND c. XOR
b. OR d. NOT

27. Exercise
Design fire alarm system using ladder diagram.