Deck 16: Programmable Logic Controllers

Question 1

Highlighting a contact means that there is a ____ through that contact.

A) complete circuit
B) short circuit
C) change of state
D) troubleshooting element

Answer 1

A

Question 2

In the relay method of isolation, the CPU is isolated through the use of a(n) ____.

A) LED
B) laser
C) electrostatic buildup
D) magnetic field

Answer 2

D

Question 3

The PLC recognizes only ____.

A) push-buttons
B) pressure switches
C) open or closed contacts
D) float switches

Answer 3

C

Question 4

What are the advantages and disadvantages of controlling output with small relays?

Question 5

Describe the power supply of the PLC.

Question 6

What are timers and counters?

Question 7

Explain the mechanism by which the differential amplifier works.

Question 8

The PLC is a special type of ____ designed to perform a special function.

A) die
B) motor
C) robotic arm
D) computer

Question 9

PLCs were first used by the ____ industry in the late 1960s.

A) railroad
B) defense
C) automotive
D) steel

Question 10

Electrical noise is such a problem in some installations that several manufacturers are using ____ instead of wires for connection to the I/O rack.

A) transistors
B) coaxial cables
C) optical cables
D) radio signals

Question 11

The most popular way to isolate the CPU from the external circuit is through ____.

A) optical isolation
B) small relays
C) rheostats
D) bridge rectifiers

Question 12

An electronic device that is often used to help overcome the problem of induced noise is the ____.

A) float switch
B) LED
C) MOV
D) differential amplifier

Question 13

The ____ is the "brains" of the PLC.

A) power supply
B) CPU
C) I/O rack
D) program loader

Question 14

What are some potential problems you might face when grounding equipment?

Question 15

The current rating of most outputs can range from 0.5 to about ____ amperes, depending on the make of the controller and the type of output being used.

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

Question 16

The actual logic of the control circuit is performed by ____.

A) physical relays
B) internal relays
C) contacts
D) RAM

Question 17

The ____ is used to connect the CPU to the load.

A) opto-isolator
B) power supply
C) input module
D) output module

Question 18

A(n) ____ is connected across the ac input to help eliminate any voltage spikes that may occur.

A) rheostat
B) metal-oxide varistor
C) avalanche diode
D) gas tube

Question 19

PLCs are designed to be programmed with ____.

A) ladder diagrams
B) BASIC
C) higher-order languages
D) relays

Question 20

The ____ is used to program the CPU.

A) I/O rack
B) power supply
C) tape deck
D) loading terminal