TPC 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

Answer 1

scan time

Question 2

The two circuits in an electromagnetic relay are the control circuit and the _______ circuit.

Answer 2

power

Question 3

Another term for a PLCs firmware is its

Answer 3

operating system

Question 4

The binary system is based on the number ________. The hexadecimal system is commonly used with PLCs is based on the number ______.

Answer 4

2; 16

Question 5

The Boolean NOT function acts as an

Answer 5

inverter

Question 6

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

Answer 6

drawn graphically

Question 7

In ladder logic, the output instruction that looks like a coil is called

Answer 7

output energize

Question 8

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

Answer 8

two

Question 9

Which of the following number systems uses both letters and number symbols

Answer 9

HEX

Question 10

Which device creates a numerically coded binary signal to represent an output condition?

Answer 10

Encoder

Question 11

The final step of a PLC scan involves

Answer 11

writing the output image table

Question 12

In Boolean programming, all logic is some combination of which operations?

Answer 12

AND, NOT, OR

Question 13

In ladder logic programming, a ________ symbol is used for input instructions, and a _______ symbol is used for output instructions

Answer 13

contact; coil

Question 14

What is the purpose of a rung comment?

Answer 14

Explain a program operation

Question 15

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

Answer 15

handshaking signal

Question 16

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

Answer 16

input terminal on an input module

Question 17

Which output device is sometimes used as a repeater, using a signal to control several different loads?

Answer 17

Relay

Question 18

If an I/O module supplies current, it is considered a ______ module

Answer 18

sourcing

Question 19

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

Answer 19

digitized

Question 20

The temperature range a thermocouple can detect is determined by the

Answer 20

combination of metals used

Question 21

Which type of signal does an incremental encoder generate?

Answer 21

chain of pulses

Question 22

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

Answer 22

fanout

Question 23

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

Answer 23

scan time

Question 24

The first step in developing a PLC system to meet given specifications is

Answer 24

sizing the system

Question 25

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

Answer 25

manufacturers

Question 26

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

Answer 26

Sequence of operation

Question 27

The most important tool a maintenance technician can possess is a

Answer 27

documentation package

Question 28

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

Answer 28

maintenance log

Question 29

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

Answer 29

annually

Question 30

Once you understand how a PLC system works, the next step in troubleshooting it is to

Answer 30

gather information

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

Most hardware problems in a PLC system occur in the

Answer 32

I/O devices

Question 33

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

Answer 33

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

Question 34

Which of the following transmission media has the highest data rate?

Answer 34

Fiber Optic cable

Question 35

Which type of data transmission uses single frequency?

Answer 35

baseband