Deck 12: Sequencer and Shift Register Instructions

Question 1

In general the two types of shift instructions are bit shift up and bit shift down.

Answer 1

False

Question 2

Sequencers are programmed exactly the same for all PLC types.

Answer 2

False

Question 3

To program a sequencer,binary information is entered into a number of random memory bits.

Answer 3

False

Question 4

Sequencer switches can be used for processes that require a repeatable operating pattern.

Question 5

Shift registers are often used for tracking parts on a production line.

Question 6

The sequencer control parameter is where the status bits,length,and instantaneous position are stored.
DIF: 245

Question 7

As a programmed sequencer advances through its steps,binary information is transferred from the sequencer file to the output word.

Question 8

When a sequencer operates on an entire output word,all outputs associated with the word are required to be controlled by the sequencer.

Question 9

The file word selectively screens out data from the sequencer word file to the output word.

Question 10

is shifted automatically through the register from one bit address to the next.

Question 11

Due to the way in which a sequencer instruction operates,all output points must be on a single output module.

Question 12

Sequencer instructions simplify your ladder program.

Question 13

Bits of an output word not used by the sequencer can be used elsewhere in your program.

Question 14

An event-driven sequencer operates in a manner similar to a mechanical drum switch that increments automatically after a preset time period.

Question 15

Many sequencer instructions reset the sequencer automatically to step 1 on completion of the last sequence step.

Question 16

The mask parameter is the address of the sequencer file.

Question 17

A time-driven sequencer advances to the next step by an external pulsed input.

Question 18

Mechanical sequencer switches are often referred to as drum switches.

Question 19

Sequencer instructions are normally nonretentive.

Question 20

There is usually no limit to the number of external outputs and steps that can be operated on by a single sequencer instruction.

Question 21

The equivalent sequencer data for step 2 of the sequencer shown would be:

A)0000000000000000
B)1111111111111111
C)0111001010101010
D)1111 0000 0011011

Question 22

You can program a shift register instruction to shift only 1's through the register.

Question 23

As the PLC sequencer advances through its steps,information is transferred from:

A)the output module to the input module.
B)the input module to the output module.
C)the programmer to the processor.
D)the word file to the output word.

Question 24

Shift registers cannot be used to control processes where parts are shifted continually from one position to the next.

Question 25

When you program a shift register instruction,you can shift data only to the left.

Question 26

For the SQO instruction shown,the ____ is the number of steps of the sequencer file.

A)Position
B)Control
C)Mask
D)Length

Question 27

For the SQO instruction shown,the ____ bit is set after the last word in the sequencer file is transferred.

A)Position
B)Control
C)EN
D)DN

Question 28

For the sequencer instruction shown,____ outputs are to be controlled from one 16-point output module.

A)6
B)15
C)16
D)24

Question 29

For the sequencer instruction shown,in step 1 ____ will be energized.

A)outputs O:2.0,O:2.5,O:2.8,O:2.11,O:2.12 and O:2.15
B)outputs O:2.2,O:2.3,O:2.10,O:2.12,and O:2.14
C)outputs O:2.0,O:2.4,O:2.6,O:2.7,O:2.9,O:2.10,and O:2.13
D)all outputs

Question 30

For the SQO instruction shown,the ____ is the address of the word used to selectively screen out data.

A)File
B)Length
C)Mask
D)Destination

Question 31

Which of the following would not be classified as a sequencer switch?

A)Rotary switch
B)Pressure switch
C)Drum switch
D)Stepper switch

Question 32

For the sequencer instruction shown,in step 2 ____ will be energized.

A)outputs O:2.0,O:2.5,O:2.8,O:2.11,O:2.12 and O:2.15
B)outputs O:2.2,O:2.3,O:2.10,O:2.12,and O:2.14
C)outputs O:2.0,O:2.4,O:2.6,O:2.7,O:2.9,O:2.10,and O:2.13
D)all outputs

Question 33

Sequencer switches are used whenever:

A)a counter function is required.
B)a timer function is required.
C)a time-delay function is required.
D)a repeatable operating pattern is required.

Question 34

For the sequencer instruction shown,in step 3 ____ will be energized.

A)outputs O:2.0,O:2.5,O:2.8,O:2.11,O:2.12 and O:2.15
B)outputs O:2.2,O:2.3,O:2.10,O:2.12,and O:2.14
C)outputs O:2.0,O:2.4,O:2.6,O:2.7,O:2.9,O:2.10,and O:2.13
D)all outputs

Question 35

For the Sequencer Output (SQO)instruction shown the ____ is the address of the output word to which the sequencer moves the data.

A)Control
B)Destination
C)Position
D)None of these are correct.

Question 36

The sequencer instruction shown reads the 16 bit data file words:

A)one bit at a time.
B)one word at a time.
C)two bits at a time.
D)two words at a time.

Question 37

The information for each PLC sequencer step is entered into:

A)the output module.
B)the input module.
C)the programmer.
D)a word file.

Question 38

If you wanted to produce an external output when a certain bit in a shift register is on,you would program a rung with an examine for on instruction corresponding to the bit address.

Question 39

As the sequencer advances through the steps,data is transferred:

A)through the sequencer file from B3:0 to B3:4.
B)through the sequencer file from B3:4 to B3:0.
C)from the output word to the sequencer file.
D)from the sequencer file to the output word.

Question 40

For the SQO instruction shown,the ____ is the starting address for the registers that contain the data to be transferred.

A)File
B)Control
C)Mask
D)Length

Question 41

For each position of the sequencer shown,data are copied from file #B3:0 through the ____ word to the destination.

A)mask
B)control
C)position
D)length

Question 42

For the sequencer instruction shown,all unmasked bits:

A)can be used elsewhere in the program.
B)cannot be used elsewhere in the program.

Question 43

When the sequencer shown is at position 2,which output(s)will be energized?

A)02/12
B)0:2/13
C)0:2/12 and 0:2/13
D)0:2/14

Question 44

When the sequencer shown is functioning,the circuit increments automatically through the ____ steps of the sequencer at ____ intervals.

A)five 3 second
B)six 3 second
C)five 3 minute
D)six 3 minute

Question 45

The sequencer program shown is:

A)motor-driven.
B)time-driven.
C)event-driven.
D)gear-driven.

Question 46

The sequencer input instruction shown is true whenever the unmasked input data are ____ the data stored in the sequencer file.

A)matched to
B)greater than
C)less than
D)greater than or equal to

Question 47

Normally,sequencer instructions are retentive.This means that,if you are at step 3 of a 10-step sequencer and power to your system is lost,when power is restored the sequencer will:

A)return to step 3.
B)increment to step 4 automatically.
C)reset to step 1 automatically.
D)advance to step 10 automatically.

Question 48

For each bit that the sequencer shown is to control,the corresponding bit of mask must be set to:

A)0
B)1
C)positive
D)negative

Question 49

When using a time-driven sequencer,the sequencer advances to the next step:

A)when the preset value equals the accumulated value.
B)when the preset value is less than the accumulated value.
C)for every true-to-false transition of the sequencer rung.
D)for every false-to-true transition of the sequencer rung.

Question 50

When the sequencer position parameter reaches 4,the ____ bit is set to 1.

A)Control
B)EN
C)DN
D)all of these

Question 51

When the sequencer instruction shown is at step 1,the binary information transferred into word O:2 would be:

A)010001
B)001010
C)100001
D)None of these are correct

Question 52

The sequencer program shown advances to the next position on each:

A)true to false transition of the sequencer rung.
B)false to true transition of the sequencer rung.
C)on power up of the PLC.
D)on power down of the PLC.

Question 53

The sequencer shown operates whenever:

A)input A is false.
B)input A is true.
C)the PLC is in the run mode.
D)the PLC is in the program mode.

Question 54

When the sequencer instruction shown is at step ___,outputs O:2/2 and O:2/3 will be on and all the rest will be off:

A)1
B)2
C)3
D)4

Question 55

A single sequencer instruction may have an upper limit on:

A)the number of steps that can be programmed.
B)the number of external outputs that can be programmed.
C)the number of times the operating cycle can be actuated.
D)both a and b.

Question 56

The sequencer instruction shown,controls ____ bits of output word O:2:

A)2
B)6
C)10
D)15

Question 57

For the sequencer instruction shown,in step 4 ____ will be energized.

A)outputs O:2.0,O:2.5,O:2.8,O:2.11,O:2.12 and O:2.15
B)outputs O:2.2,O:2.3,O:2.10,O:2.12,and O:2.14
C)outputs O:2.0,O:2.4,O:2.6,O:2.7,O:2.9,O:2.10,and O:2.13
D)all outputs

Question 58

The sequencer shown advances its position whenever:

A)S1 makes a false to true transition.
B)S2 makes a false to true transition.
C)the PLC is in the run mode.
D)either a or b.

Question 59

A program modification is to be made to the sequencer shown that requires outputs O:2/12,O:2/13,O:2/14 and O:2/15 to all be energized at step 3.This would require:

A)bits 12,13,14 and 15 of word B3:22 to be set to 1.
B)bits 13,14 and 15 of word B3:23 to be set to 1.
C)bits 12,14 and 15 of word B3:24 to be set to 1.
D)bits 14 and 15 of word B3:25 to be set to 1.

Question 60

The sequencer program shown is:

A)motor-driven.
B)time-driven.
C)event-driven.
D)gear-driven.

Question 61

The sequencer compare program shown increments the position parameter whenever:

A)the unmasked input data match the data stored in the sequencer file.
B)the unmasked input data does not match the data stored in the sequencer file.
C)input I:1/0 makes a false to true transition.
D)input I:1/0 makes a true to false transition.

Question 62

A bit shift register operates synchronously in that:

A)information is shifted one bit at a time within a word or words.
B)for every bit shifted in,one is shifted out.
C)the data entered must be shifted the length of the register before it is available to be shifted out.
D)all of these.

Question 63

In this example the data at position ____ matches the unmasked input data making the PL1 output ____.

A)2,true
B)2,false
C)4,true
D)4,false

Question 64

The sequencer load instruction shown,____data from the source to the sequence file.

A)adds
B)subtracts
C)copies
D)negates

Question 65

When the SQI instruction is paired with the SQO instruction as illustrated:

A)the same control address,length value,and position value is used for each instruction.
B)the sequencer input instruction is indexed by the sequencer output instruction.
C)it allows input and output sequences to function in unison.
D)all of these.

Question 66

A bit shift register shifts bits:

A)serially from bit to bit.
B)serially between words.
C)randomly from bit to bit.
D)randomly between word.

Question 67

The sequencer load instruction shown:

A)does not function during the machines normal operation.
B)replaces manual loading of data into the sequencer file.
C)does not use a mask.
D)all of these.

Question 68

For the bit shift left (BSL)register shown file length is given in:

A)words.
B)bits.
C)steps.
D)files.

Question 69

In a word shift register,the data are shifted out ___bit(s)at a time.

A)1
B)2
C)4
D)16

Question 70

The found bit (FD)of the SQC program shown,is set true to1 whenever the:

A)instruction is true.
B)source pattern matches the sequencer file word.
C)source pattern does not match the sequencer file word.
D)PLC is powered on.

Question 71

A common application for a shift register would be:

A)tracking parts.
B)controlling machine or process operations.
C)inventory control.
D)all of these.