Question 1

____ coils revert to their de-energized state whenever the PLC is cycled from stop to run or whenever the power is cycled.
A) Retentive
B) Nonretentive
C) Negative
D) Open

Accepted Answer

Nonretentive coils revert to their de-energized state whenever the PLC is cycled from stop to run or whenever the power is cycled. Retentive coils maintain their state even after a power cycle or when the PLC is cycled from stop to run. Negative and open are not relevant terms in this context.

Question 2

A(n) ____ output module will produce output signals that are either 0 to 10 VDC or 4 to 20 milliamperes.
A) analog
B) digital
C) differential
D) variable

Accepted Answer

An analog output module produces output signals that are in the form of continuous voltage or current levels. The options given are 0 to 10 VDC or 4 to 20 milliamperes, which are both forms of analog signals. Digital output modules produce binary signals, while differential and variable output modules have different functions and characteristics.

Question 3

____ timers will retain their timed value during a loss of power.
A) Retentive
B) Nonretentive
C) On-delay
D) Off-delay

Accepted Answer

Retentive timers have the ability to retain their timed value even during a loss of power. Nonretentive timers, on the other hand, will reset their value to zero during a power loss. On-delay and off-delay timers refer to the way the timer functions in relation to the activation signal and do not relate to their ability to retain their value during a power loss.

Question 4

___ coil is a nonretentive coil used to perform a latch function.
A) SET
B) RESET
C) LET
D) TLC

Accepted Answer

A SET coil is used in ladder logic programming for PLCs (Programmable Logic Controllers) to perform a latch function, allowing the output to remain active even after the input condition is no longer true.

Question 5

Digital input modules are available for DC inputs, AC inputs, or a mix.

Accepted Answer

Digital input modules are available for different types of inputs, including DC and AC inputs, and can also handle a mix of inputs.

Question 6

Which is a PLC program control instruction?
A) LOCATION
B) SEND
C) MRC
D) ENDMCR

Accepted Answer

ENDMCR is a PLC program control instruction used to mark the end of a master control relay section in a program.

Question 7

The five programming languages for PLCs are the ladder diagram, the function block diagram, the instruction list, the sequential function chart and the structured graphic.

Accepted Answer

The five programming languages for PLCs are the ladder diagram, the function block diagram, the instruction list, the sequential function chart, and the structured text, not structured graphic.

Question 8

____ timers perform a timing function while receiving power. The state of the associated contact(s) do not change until the timer has timed out.
A) Coil
B) Off-Delay
C) On-delay
D) End

Accepted Answer

On-delay timers start timing when power is applied, and the contacts change state only after the set time has elapsed.

Question 9

Which PLC language is a BASIC style language?
A) Sequential Function Chart
B) Structured Text
C) Ladder Diagram
D) Instruction List

Accepted Answer

Structured Text is a BASIC-style language that uses familiar programming structures like IF-THEN-ELSE statements and loops. It is similar to the language used in programming PC applications, and is particularly useful for complex algorithms or mathematical calculations.

Question 10

Down-counters perform a counting function when the associated input element transitions from a(n) ____ to a(n) ____ state.
A) on, off
B) off, on
C) on, reset
D) off, reset

Accepted Answer

Down-counters count down the occurrences of the input transition from "on" to "off" state. This transition is also called a falling edge. Therefore, option B, where the input element transitions from "off" to "on" state, cannot trigger the counting function of a down-counter.

Question 11

Most PLCs consist of an assortment of modules (input and output), a CPU, a power supply, and a rack in which to mount the modules.

Accepted Answer

This is correct as it describes the typical components of a PLC system.

Question 12

One big advantage of using point-to-point wiring of relay controls over a PLC is that the wiring is greatly simplified and reduced.

Accepted Answer

Point-to-point wiring of relay controls typically involves more complex and extensive wiring than using a Programmable Logic Controller (PLC), which centralizes control and can significantly reduce the amount of wiring needed.

Question 13

Instruction List is a low-level program best suited for small applications and fast execution.

Accepted Answer

Instruction List is a low-level programming language that is optimized for small applications and fast execution. It is often used in industrial control systems and other real-time applications where speed and efficiency are critical.

Question 14

The Function Block Diagram is a(n) ____ language.
A) graphical
B) text-based
C) BASIC style
D) C++ style

Accepted Answer

The Function Block Diagram language uses graphical representation to depict the functions, inputs, outputs, and interconnections between elements.

Question 15

A PLC will treat all inputs and output sources the same; they will be looked upon as a(n) ____.
A) signal
B) voltage source
C) resistance
D) load

Accepted Answer

The answer of A PLC will treat all inputs and...

Quiz 24: Programmable Logic Controllers

____ coils revert to their de-energized state whenever the PLC is cycled from stop to run or whenever the power is cycled.

A(n) ____ output module will produce output signals that are either 0 to 10 VDC or 4 to 20 milliamperes.

____ timers will retain their timed value during a loss of power.

___ coil is a nonretentive coil used to perform a latch function.

Digital input modules are available for DC inputs, AC inputs, or a mix.

Which is a PLC program control instruction?

The five programming languages for PLCs are the ladder diagram, the function block diagram, the instruction list, the sequential function chart and the structured graphic.

____ timers perform a timing function while receiving power. The state of the associated contact(s) do not change until the timer has timed out.

Which PLC language is a BASIC style language?

Down-counters perform a counting function when the associated input element transitions from a(n) to a(n) state.

Most PLCs consist of an assortment of modules (input and output), a CPU, a power supply, and a rack in which to mount the modules.

One big advantage of using point-to-point wiring of relay controls over a PLC is that the wiring is greatly simplified and reduced.

Instruction List is a low-level program best suited for small applications and fast execution.

The Function Block Diagram is a(n) ____ language.

A PLC will treat all inputs and output sources the same; they will be looked upon as a(n) ____.