Deck 11: Math Instructions

Question 1

Math instructions enable the programmable controller to take on some of the qualities of a computer system.

Answer 1

True

Question 2

Assume output 0:3/2 is energized and the values of the numbers stored in words N7:0 and N7:1 are 500 and 40,respectively.The value of the number stored in word N7:8 would be 13.

Answer 2

True

Question 3

The ability of a PLC to perform math functions is intended to allow it to replace a calculator.

Answer 3

False

Question 4

The rung logic is telling the processor to subtract the value stored in word N7:20 from the value stored in word N7:10.

Question 5

If output 0:5/8 is to be energized when the product of the values stored in words N7:1 and N7:2 is equal to 5 and 20,then the value of the number stored in word N7:4 must be 1000.

Question 6

The program is telling the processor to energize output 0:6/2 whenever the value of N7:8 is equal to that of N7:4.

Question 7

All PLC manufacturers use the same format for math instructions.

Question 8

The program is telling the processor to energize output 0:2/3 whenever the sum of N7:5 and N7:8 is greater or equal to that of N7:4.

Question 9

File arithmetic instructions are designed to perform math operations on single words.

Question 10

The rung logic is telling the processor to divide the value of word N7:4 by the value of N7:6.

Question 11

The rung logic is telling the processor to add the values stored in word N7:1 and N7:2.

Question 12

PLCs can use numerical data from the accumulated values of timers and counters with math functions.

Question 13

The rung logic is telling the processor to multiply the values stored in word N7:2 and N7:1.

Question 14

The negate instruction is used to change the sign of a number.

Question 15

When the input goes true,the value will be stored in F8:1 will be 24.8.

Question 16

Integer files are used to store numerical data that are used by math functions.

Question 17

Destination is where the result of the instruction is stored.

Question 18

Source is a value that is an input to the instruction.

Question 19

Math instructions are all output instructions.

Question 20

There is no limit to the maximum value a PLC math function can store.

Question 21

The number stored in word N7:1 represents the:

A)weight of the empty vessel.
B)preset weight of the vessel.
C)current weight of the vessel.
D)difference between the current and preset weight of the vessel.

Question 22

PLC math functions perform arithmetic on values stored in memory words.
Multiple Choice Questions

Question 23

Assume the value stored in N7:1 changes from 30 to 10.Which value stored in N7:4 will result in PL1,being energized?

A)10
B)25
C)35
D)50

Question 24

The amount of overfill weight required to trigger the alarm is changed by changing:

A)the value of the number stored at input 1:012.
B)the value of source B of the GEQ instruction of rung 3.
C)the value of source B of the GEQ instruction of rung 5.
D)the value of the number stored in word N7:1.

Question 25

When the Full light is on:

A)the weight of the vessel is 500 pounds or more.
B)rung No.3 is always true.
C)rung No.1 is always false.
D)all of these.

Question 26

The number stored in N7:2 would be:

A)85.
B)28.
C)181.
D)285.

Question 27

Which of the following numbers stored in N7:3 will cause output PL1 to be energized?

A)048
B)124
C)172
D)325

Question 28

The preset full weight of the vessel is changed by changing:

A)the value of the number stored at input 1:012.
B)the value of source B of the GEQ instruction of rung 3.
C)the value of source B of the GEQ instruction of rung 5.
D)the value of the number stored in word N7:1.

Question 29

What number stored in N7:3 will turn PL1 on?

A)150
B)100
C)50
D)all of these

Question 30

In the program shown,the value of the number stored in N7:2 is:

A)172.
B)601.
C)325.
D)348.

Question 31

Assume that the light is to come on after a total count of 120.As a result:

A)the preset counter C5:0 must be changed to 120.
B)the value in source B of the GEQ instruction must be changed to 120.
C)the value in source B of the ADD instruction must be changed to 120.
D)the value in word N7:1 must be changed to 120.

Question 32

Rung No.2 will be true:

A)at all times.
B)when the number stored in word N7:1 is equal to 48.
C)when the number stored in word N7:1 is less than 48.
D)when the number stored in word N7:1 is greater than 48.

Question 33

The ability of a PLC to perform math functions is intended to:

A)replace a calculator.
B)multiply the effective number of input and output devices.
C)perform arithmetic functions on values stored in memory words.
D)all of these.

Question 34

The number stored in N7:3 is:

A)6.
B)60.
C)150.
D)300.

Question 35

When the Filling light is on:

A)the weight of the vessel is less than 500 pounds.
B)rung No.2 is always true.
C)rung No.4 is always false.
D)all of these.

Question 36

The number stored in N7:1 represents the:

A)upper temperature limit.
B)lower temperature limit.
C)current temperature of the oven.
D)difference between the preset and current temperature.

Question 37

PL1 will be on whenever the current temperature is:

A)greater than the preset temperature.
B)less than the preset temperature.
C)greater than the upper temperature limit.
D)less than the lower temperature limit.

Question 38

Assume the accumulated count of counter C5:0 and C5:1 to be 124 and 248,respectively.As a result:

A)the number 372 will be stored in word N7:1 and output PL1 will be energized.
B)the number 372 will be stored in word N7:1 and output PL1 will not be energized.
C)the number 350 will be stored in word N7:1 and output PL1 will be energized.
D)the number 350 will be stored in word N7:1 and output PL1 will not be energized.

Question 39

For the program of Figure 11-6,the set-point temperature is set by the number stored in:

A)N7:0.
B)N7:2.
C)1:012.
D)1:013.

Question 40

For the program as shown,output PL1:

A)would be energized.
B)would not be energized.

Question 41

The value of the number stored in N7:1 is:

A)90.
B)45.
C)35.
D)60.

Question 42

The value of the number stored in 1:012 is:

A)25.
B)30.
C)35.
D)40.

Question 43

The value of the number stored in N7:0 is:

A)225.
B)500.
C)750.
D)230.

Question 44

Math instructions are all ____ instructions.

A)output
B)input
C)binary
D)BCD

Question 45

Which math instruction would you use if you wanted to calculate the difference between the accumulated values of two counters?

A)ADD
B)SUB
C)MUL
D)DIV

Question 46

Assume the set-point temperature is changed to 200 $\degree$ F.As a result,the number stored in N7:0 would be:

A)2.
B)4.
C)6.
D)8.

Question 47

The number stored in N7:5 would be:

A)1000.
B)500.
C)4.
D)2.

Question 48

The value of the number stored in 0:013 is:

A)98.
B)77.
C)67.
D)57.

Question 49

For the ADD instruction shown,the ____ used as part of the expression is a constant.

A)Source A
B)0
C)300
D)N7:20

Question 50

The value of the number stored at Destination is:

A)17
B)16.666
C)50
D)51

Question 51

File arithmetic functions are used to perform arithmetic operations on:

A)multiple words.
B)integer numbers only.
C)decimal numbers only.
D)BCD numbers only.

Question 52

Which math instruction would you use if you wanted to take the opposite sign of a value?

A)SUB
B)SQR
C)NEG
D)CLR

Question 53

The value of the number stored at Destination is:

A)293
B)-193
C)51
D)-342

Question 54

Assume the upper and lower temperature limits are programmed for 2% instead of 1% and the preset is 400 $\degree$ F.As a result,the number stored in N7:2 would be:

A)392.
B)390.
C)388.
D)386.

Question 55

The value of the number stored at Source B is:

A)N7:8
B)N7:16
C)328
D)528

Question 56

The ADD instruction is telling the processor to add the:

A)preset and current temperatures.
B)upper and lower temperature limits.
C)current and upper limit temperatures.
D)preset and upper deadband range.

Question 57

Which constant stored in source B of the EQU instruction would turn PL1 on?

A)24
B)20
C)6
D)4

Question 58

The value of the number stored at N7:30 is:

A)5
B)15.5
C)4.87
D)1.85

Question 59

Assume the value stored in N7:0 is 90,the value stored at N7:1 is 3 and the constant for source B of the EQU instruction is 10.What would the state of PL1 be?

A)Off
B)On