Intro to PLCs L1-7

Question 1

____ is the connection of all exposed current-carrying metal parts to earth.

Answer 1

Grounding

Question 2

Proper PLC grounding includes grounding a conductor shield at ____ point(s).

Answer 2

only one

Question 3

An electrical enclosure provides the main protection for a PLC from ____ conditions.

Answer 3

atmospheric

Question 4

The lower the ____, the greater the current flow and greater the severity of electric shock.

Answer 4

resistance

Question 5

A(n) ___ is a dual-voltage unit used to set the power rating of a PLC.

Answer 5

Jumper Link

Question 6

____ grounding is the connection of machinery electrical systems to earth ground to reduce the chance of electrical shock by grounding all non–current-carrying exposed metal.

Answer 6

Equipment

Question 7

____ is any unwanted signal present on power lines.

Answer 7

Electrical noise

Question 8

What is the third step in the OSHA lockout/tagout procedure?

Answer 8

Isolate machinery or equipment.

Question 9

A(n) ____ signal continuously changes in value between defined limits.

Answer 9

analog

Question 10

A ____ is the negative power supply terminal of a DC-powered PLC.

Answer 10

sink

Question 11

Sinks use conventional electron flow through an ____ transistor.

Answer 11

NPN

Question 12

A ____ shows what a device looks like, but does not give accurate dimensions or other specific detailed information.

Answer 12

pictorial drawing

Question 13

Standard ____ components include pushbutton, limit, and pressure switches.

Answer 13

intput

Question 14

There are ____ basic methods of wiring electrical circuits.

Answer 14

three

Question 15

A ____ is a graphic element that represents a quantity, unit, device, or component.

Answer 15

symbol

Question 16

A ____ is a drawing that shows the electrical connection of all devices and components to a PLC.

Answer 16

wiring diagram

Question 17

All PLCs are considered “____” electrical equipment.

Answer 17

open-type

Question 18

When programming a PLC contact, ____ can be added to the generic symbol.

Answer 18

words

Question 19

A(n) ____ is designed to suppress voltage spikes.

Answer 19

snubber circuit

Question 20

The number and type of I/Os cannot be changed in a ____ PLC.

Answer 20

fixed

Question 21

CPUs are rated according to the size of the program memory and ____.

Answer 21

scan time

Question 22

Low AC voltages __ - __ V are used for doorbells, security systems, and as a voltage level for PLC inputs.

Answer 22

6-24V

Question 23

What are typical PLC size classifications?

Answer 23

Nano/pico, micro, medium/small, and large

Question 24

XIC instructions are ____ instructions.

Answer 24

input

Question 25

Which unit is the smallest unit of memory?

Answer 25

bit

Question 26

For an output device to affect another instruction during a specific scan, the instruction must be in a rung ____ the output.

Answer 26

below

Question 27

____ instructions are located in data table file 5.

Answer 27

Counter

Question 28

Typically, RES instructions are used only with ___, ___, or ___ instructions.

Answer 28

RTO, CTU, or CTD

Question 29

____ timers can also be used to start equipment sequentially.

Answer 29

Cascaded

Question 30

____ timers are generally used to pulse outputs such as lights.

Answer 30

Free-running

Question 31

OTL can only turn a bit ____.

Answer 31

ON

Question 32

OTU can only turn a bit ____.

Answer 32

OFF

Question 33

____ relays draw high current when energized, producing high voltage spikes.

Answer 33

Electromechanical

Question 34

A ____ is a completely isolated circuit (contact) that can be switched by a relay.

Answer 34

pole