298 Programmable Logic Controllers

Question 1

The time it takes a programmable controller to run through its program and return to the beginning is called ______ time

Answer 1

Scan

Question 2

The logical decisions of a programmable controller are made in the

Answer 2

processor

Question 3

Which of the following PLC elements give the system flexibility?

Answer 3

Program

Question 4

The binary system is based on the number______ The hexadecimal system commonly used with PLCs is based on the number______

Answer 4

2; 16

Question 5

The code most often used to represent alphanumerics

Answer 5

ASCII

Question 6

The Boolean NOT function acts as an)

Answer 6

inverter

Question 7

Ladder logic differs from most other computer languages in that it is

Answer 7

drawn graphically

Question 8

Which digit is the most significant in the number 2684?

Answer 8

2

Question 9

In the binary system, each bit has a weight of _____ times the digit to the right of it.

Answer 9

TWO

Question 10

Although an output generally appears on only one rung of a ladder logic program, it may be energized by several sets of conditions that appear as

Answer 10

branches

Question 11

When a ladder logic program is written as part of a larger program an) ____ is used to tell it when to start its sequence

Answer 11

handshaking signal

Question 12

Boolean logic is written in _____ form

Answer 12

Listing

Question 13

most PLC applications, each pushbutton contact is wired to an)

Answer 13

input terminal on an input module

Question 14

The function of a float switch is to indicate

Answer 14

Liquid level

Question 15

To be useful to a PLC, analog input signals must be ____ by an input module

Answer 15

Digitized

Question 16

The temperature range a thermocouple can detect is determined by the

Answer 16

combination of metals used

Question 17

The number of TTL output devices a TTL output module can drive is called

Answer 17

Fanout

Question 18

Working with accurate, thorough specifications ensures that

Answer 18

all efforts move toward a common target

Question 19

When sizing a programmable controller system, you must consider I/O, memory, and

Answer 19

Scan time

Question 20

The first step in developing a PLC system to meet given specitications Is

Answer 20

sizing the system

Question 21

Before turning a newly designed and installed system over to production, use the output disable function and indicating lights to check for correct

Answer 21

Input wiring

Question 22

The easiest way to develop a PLC program is usually to divide the logic into different

Answer 22

Tasks

Question 23

Which hardware documentation drawing identifies all system components and wiring termination points?

Answer 23

Panel layout

Question 24

A bill of material should include a complete list of part numbers, device numbers cross-referenced in the drawing, and part

Answer 24

Manufacturers

Question 25

Which of the following documents walks you through the complete PLC system operation?

Answer 25

Sequence of operation

Question 26

The most important tool a maintenance technician can possess is an

Answer 26

Documentation package

Question 27

Information concerning parts replacements, adjustments, and other system changes can be found in the

Answer 27

maintenance log

Question 28

When control components fail, the problem is most often related to

Answer 28

Dirt

Question 29

As a good general rule, you should replace the battery in a programmable controller

Answer 29

Annually

Question 30

Which documentation shows how all field devices are wired and connected to the controller?

Answer 30

Schematic diagram

Question 31

Which of the following is the most common cause of a program problem?

Answer 31

Changes made to the original program

Question 32

Which of the following is a recommended test strategy for troubleshooting?

Answer 32

Start at the switch and test each connection until you reach the controller

Question 33

The process of relating software addresses to the physical locations of remote 1/0 points is called _____ the system

Answer 33

Configuring

Question 34

A LAN application in which information stored in different drops is collected at a central location is known as

Answer 34

data acquisition

Question 35

Adding I/O points in an existing rack is called

Answer 35

local expansion