Deck 5: Basics of Plc Programming

Question 1

When there is a True logic rung path,all parallel outputs in the rung become True.

Answer 1

True

Question 2

The status of the OTE instruction is set to 1 to energize the output and to 0 to de-energize the output.

Answer 2

True

Question 3

When the XIC instruction is associated with a physical input,the instruction will be set to 1 when there is no input voltage applied to the terminal.

Answer 3

False

Question 4

The user program contains the logic that controls the machine operation.

Question 5

When the XIO instruction is associated with a physical input,the instruction will be set to 1 when there is no input voltage applied to the terminal.

Question 6

Most instructions require one word of memory.

Question 7

Each individual contact instruction can be used only once throughout the program.

Question 8

If any input signal changes state very quickly,it is possible that the controller may never be able to detect the change.

Question 9

All PLC manufacturers organize their memories in the same way.

Question 10

The status of input and output devices is stored in a data table.

Question 11

On some PLC models,branches can be established at both the input and output portions of a rung.

Question 12

The memory organization of a PLC is often called a memory map.

Question 13

The rung condition and OTE instruction are false if no logical continuity path has been established.

Question 14

It takes the processor exactly the same amount of time to examine different types of instructions.

Question 15

There may be a limit to the number of series contact instructions that can be included in one rung of a ladder logic program.

Question 16

Misunderstanding the way the PLC scans a program can cause programming bugs.

Question 17

Both normally open and normally closed pushbuttons can be represented by the XIC or XIO instruction.

Question 18

The addressing format for inputs and outputs is standard for all PLC models.

Question 19

The greater the scan time,the faster the PLC can react to changes in inputs.

Question 20

Scan time varies with program content and length.

Question 21

The status bit of switches and pushbuttons connected to a PLC are stored in the:

A)input image table file.
B)output image table file.
C)user program.
D)all of these.

Question 22

For the scan process shown,step 2 involves:

A)solving the ladder program.
B)transferring data to the output module.
C)transferring data to the input module.
D)reading data from the input module.

Question 23

Which of the following is a factor in determining the total scan time?

A)Length of the ladder program.
B)Type of instructions executed.
C)Speed of the processor.
D)All of these.

Question 24

The memory organization of a PLC can be divided into two broad categories:

A)Input and output image files
B)Timer and counter files
C)Program and data files
D)Control and integer

Question 25

The output data is sent to the:

A)output field devices.
B)output module.
C)input module.
D)ladder program.

Question 26

The scan is normally a sequential process of:

A)reading the control logic,evaluating the outputs,and updating the inputs.
B)writing the control logic,evaluating the outputs,and updating the inputs.
C)reading/writing the status of inputs and updating the outputs.
D)reading the status of inputs,evaluating the control logic,and energizing or de-energizing the outputs.

Question 27

The address for the point on the I/O module would be:

A)I:2/8
B)I:8/2
C)O:8/2
D)O:2/8

Question 28

The _________ will account for most of the total memory of a given PLC system.

A)input image table file
B)output image table file
C)user program
D)internal operating instructions

Question 29

Series logic could also be called OR logic.

Question 30

Ladder logic is still the most common PLC programming language.

Question 31

Coils are output instructions.

Question 32

For the input module shown,the data stored in the word corresponding to the open switch would be ___ and that for the closed switch would be ___ respectively.

A)1,1
B)0,1
C)0,0
D)1,0

Question 33

Contacts are output instructions.

Question 34

For the scan process shown,the input data is provided by the:

A)ladder program.
B)output module.
C)input module.
D)all of these.

Question 35

Ladder logic is a symbolic language.

Question 36

If a PLC has a total scan time of 10 ms and has to monitor a signal that _____ then the controller may not detect this change.

A)changes state once in 20 ms
B)is fast
C)is constantly changing
D)changes state twice in 5 ms

Question 37

The address for the point on the I/O module shown would be:

A)I:6/1
B)I:1/6
C)O:6/1
D)O:1/6

Question 38

An internal output does not directly control an output field device.

Question 39

Parallel logic could also be called AND logic.

Question 40

According to the data stored in the word corresponding to the outputs,PL1 would be ____,and PL2 would be ___ respectively.

A)on,on
B)off,off
C)on,off
D)off,on

Question 41

Which of the following input combinations will result the Y output being energized?

A)A and B and C and D
B)A and not B and not C and D
C)E and D
D)E and not D

Question 42

Branch input instructions are used to create a:

A)series path of input instructions.
B)parallel path of input instructions.
C)serial connection of input modules.
D)parallel connection of input modules.

Question 43

The most likely module address for PL1 is:

A)I:3/6
B)I:6/3
C)O:3/6
D)O:6/3

Question 44

A ladder rung is said to have logic continuity when:

A)at least one left-to-right true logical path exists.
B)all input instructions are at a logic 1.
C)all input instructions are at a logic 0.
D)both a and b

Question 45

The Output Energize instruction:

A)is also known as the OTE instruction.
B)signals the PLC to energize or deenergize the output.
C)looks and operates like a relay coil.
D)all of these.

Question 46

A programmed XIO instruction:

A)with a bit status of 1 will not have logic continuity.
B)is examined for an OFF condition.
C)is examined for an ON condition.
D)both a and b.

Question 47

The two types of patterns used to accomplish the scan function are:

A)horizontal and vertical.
B)left and right.
C)up and down.
D)input and output.

Question 48

For the program shown,instruction B represents an:

A)Examine If Closed instruction.
B)Examine If Open instruction.
C)Output Energize instruction.
D)Input Energize instruction.

Question 49

The actual scan time is:

A)calculated and stored in the PLC's memory.
B)computed each time the END instruction is executed.
C)the time taken to scan inputs and outputs and execute the user program.
D)all of these.

Question 50

The ____ instructions always interpret a 1 status as true and a 0 status as false.

A)XIC
B)XIO
C)contact
D)all of these

Question 51

For the program shown,instruction A represents an:

A)Examine If Closed instruction.
B)Examine If Open instruction.
C)Output Energize instruction.
D)Input Energize instruction.

Question 52

A programmed XIC instruction:

A)with a bit status of 1 will have logic continuity.
B)with a bit status of 0 will have logic continuity.
C)is examined for an OFF condition.
D)both b and c.

Question 53

A(n)_____ scan pattern examines instructions rung by rung.

A)horizontal
B)vertical
C)input
D)output

Question 54

The addressing format used with PLCs:

A)is standard for all PLCs.
B)indicates what PLC input is connected to what input device.
C)indicates what PLC output is connected to what output device.
D)both b and c.

Question 55

The PLC program shown is a ___ type.

A)Structured Text
B)Functional Block Diagram
C)Ladder Diagram
D)None of these are correct

Question 56

Which of the following standard PLC programming languages is a graphical language?

A)Function Block Diagram
B)Ladder Diagram
C)Sequential Function Chart
D)all of these

Question 57

For the program shown,instruction,Y represents an:

A)Examine If Closed instruction.
B)Examine If Open instruction.
C)Output Energize instruction.
D)Input Energize instruction.

Question 58

The Examine If Closed instruction:

A)is also known as the Examine-On instruction.
B)is also known as the XIC instruction.
C)looks and operates like a normally open relay contact.
D)all of these.

Question 59

The most likely module address for LS1 is:

A)LS1 I2
B)LS1 O2
C)I:2/2
D)O:2/2

Question 60

The Examine If Open instruction:

A)is also known as the Examine-Off instruction.
B)is also known as the XIO instruction.
C)looks and operates like a normally closed relay contact.
D)all of these.

Question 61

The bit status condition of the input device shown connected to address I:2/8 must be ___ to turn on output address O:3/6.

A)0
B)1
C)normally open
D)normally closed

Question 62

The Boolean equation for the logic represented in the ladder diagram can be expressed as:

A)Y = (AB)+ (ACD)+ (DE)
B)Y = (AB)+ (ACD)+ (DE)+ (BCE)
C)Y = (AB)+ (AC)+ (AD)+ (ED)
D)Y= (AB)+ (CD)+ E

Question 63

When the PLC is required to operate the user program without energizing any outputs,it is placed in the ___ mode.

A)RUN
B)CLEAR MEMORY
C)PROGRAM
D)TEST

Question 64

The address O:3/7 would be found on terminal ____ of an output module residing in slot ___ of the PLC chassis.

A)3,7
B)7,3
C)4,7
D)7,4

Question 65

When using an XIC instruction,the reference address could be:

A)a bit from an input device.
B)a bit from an output device.
C)a bit from an internal relay.
D)any of these.

Question 66

For the matrix limitation diagram shown,the maximum number of rungs allowed is:

A)one.
B)four.
C)five.
D)limited only by the memory size.

Question 67

When a program rung consists of an output instruction only,the output would then be:

A)continuously ON.
B)continuously OFF.
C)shorted.
D)both a and c.

Question 68

With reference to the program shown,if it could be programmed as shown,part of the logic would be ignored due to the fact that the processor allows for a flow:

A)from right to left only.
B)from left to right only.
C)in the upward direction only.
D)both a and c.

Question 69

For the matrix limitation diagram shown,maximum number of outputs allowed per rung is:

A)one.
B)four.
C)five.
D)limited only by the memory size.

Question 70

The Boolean equation for the logic represented in the ladder logic program shown can be expressed as:

A)Y = (A)+ (CD)+ (BC)
B)Y= A + B + (CD)
C)Y = (AB)+ (CD)
D)Y = A(BCD)

Question 71

For the matrix limitation diagram shown,the maximum number of parallel rows allowed is:

A)one
B)four
C)five
D)limited only by the memory size

Question 72

The highlighted rungs in the program rung shown indicate:

A)the instruction is true.
B)the instruction is false.
C)the instruction does not have logic continuity.
D)both b and c.

Question 73

The last element to be entered on a ladder rung is a(n):

A)coil.
B)contact.
C)XIC instruction.
D)XIO instruction.

Question 74

The address I:1/3 identifies an input module residing in slot ___ of the PLC chassis.

A)zero
B)one
C)two
D)three

Question 75

In ladder logic programs,outputs are represented by:

A)contact symbols.
B)coil symbols.
C)schematic load device symbols.
D)either a or b.

Question 76

Parallel connections of ladder logic are typically called:

A)rungs.
B)networks.
C)coils.
D)branches.

Question 77

An internal control relay:

A)does not directly control an output field device.
B)is not controlled by the programmed logic.
C)is used primarily to control the internal power to the processor module.
D)is used primarily when controlling multiple output circuits.

Question 78

For the matrix limitation diagram shown,maximum number of series contacts allowed per rung is

A)one.
B)four.
C)five.
D)limited only by the memory size.

Question 79

Each complete horizontal line of a ladder diagram is generally referred to as a(n):

A)rung.
B)branch.
C)input.
D)output.

Question 80

A normally open limit switch is wired to an input module,and programmed using XIO instruction.The instruction will be true when:

A)power is applied and the PLC is in the run mode.
B)the limit switch is closed.
C)the limit switch is open.
D)never.