Michigan PLC Programmer Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. What is the primary function of a PLC in industrial automation?
A. Generate electrical power
B. Control machinery and processes
C. Replace human operators entirely
D. Design mechanical components
A PLC’s main purpose is to execute control logic to monitor and
operate industrial machinery and processes.
2. In ladder logic, what does a normally open (NO) contact represent?
A. A permanently closed circuit
B. A sensor that fails safe
C. A condition that must be true to allow current flow
D. A contact that never changes state
A normally open contact only allows current when the corresponding
input or condition is true.
3. A PLC scan cycle consists of input scan, program execution, and output
update. Which step happens first?
A. Program execution
B. Output update
C. Diagnostics check
D. Input scan
The PLC first reads all input statuses before executing logic.
4. Which of the following languages is defined in IEC 61131-3 for PLC
programming?
A. Python
, B. HTML
C. Structured Text
D. Java
Structured Text is one of the standardized PLC programming
languages under IEC 61131-3.
5. What does “rising edge” detection do in PLC logic?
A. Triggers on input held low
B. Triggers when input goes from high to low
C. Triggers continuously while input is high
D. Triggers once when input goes from low to high
Rising edge detection identifies the moment a signal transitions from
false to true.
6. In a PLC, what is meant by “scan time”?
A. Time to replace worn components
B. Time to write new logic
C. Time between physical maintenance checks
D. Time for one full execution cycle of the CPU
Scan time refers to how long it takes for a PLC to read inputs, process
logic, and update outputs.
7. Which file type is commonly used to store PLC program logic on a PC?
A. .docx
B. .jpg
C. .prg
D. .mp3
A .prg or similar extension is used for PLC programs in many software
environments.
8. What is the purpose of a PLC’s watchdog timer?
A. Increase output voltage
B. Log operator actions
C. Predict hardware failures
D. Detect program or hardware faults
A watchdog timer resets the PLC if it stops functioning normally.
9. A PLC’s discrete input module typically reads signals of what type?
A. Analog voltage
B. RF signals
, C. Light intensity
D. On/Off digital signals
Discrete input modules detect binary states such as switches or
contact closures.
10. Which device converts analog signals into digital values for a
PLC?
A. Transformer
B. Motor
C. Encoder
D. Analog-to-digital converter (ADC)
An ADC is used to translate real-world analog values into digital data
for the PLC.
11. In ladder logic, a coil represents what?
A. A transistor
B. A timer only
C. An output or internal bit
D. A power supply
A coil energizes an output or sets an internal relay bit based on logic
conditions.
12. Which PLC memory area stores the user program?
A. Backup battery
B. Display buffer
C. Network cache
D. Program memory
Program memory holds the user’s control logic instructions.
13. What’s the function of a PLC timer TON?
A. Count items
B. Convert inputs
C. Delay turning on outputs after input becomes true
D. Measure frequency
TON (Timer On Delay) delays activation of an output once conditions
are met.
14. A PLC counter that increases on each signal is called:
A. Down counter
B. Linear counter
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. What is the primary function of a PLC in industrial automation?
A. Generate electrical power
B. Control machinery and processes
C. Replace human operators entirely
D. Design mechanical components
A PLC’s main purpose is to execute control logic to monitor and
operate industrial machinery and processes.
2. In ladder logic, what does a normally open (NO) contact represent?
A. A permanently closed circuit
B. A sensor that fails safe
C. A condition that must be true to allow current flow
D. A contact that never changes state
A normally open contact only allows current when the corresponding
input or condition is true.
3. A PLC scan cycle consists of input scan, program execution, and output
update. Which step happens first?
A. Program execution
B. Output update
C. Diagnostics check
D. Input scan
The PLC first reads all input statuses before executing logic.
4. Which of the following languages is defined in IEC 61131-3 for PLC
programming?
A. Python
, B. HTML
C. Structured Text
D. Java
Structured Text is one of the standardized PLC programming
languages under IEC 61131-3.
5. What does “rising edge” detection do in PLC logic?
A. Triggers on input held low
B. Triggers when input goes from high to low
C. Triggers continuously while input is high
D. Triggers once when input goes from low to high
Rising edge detection identifies the moment a signal transitions from
false to true.
6. In a PLC, what is meant by “scan time”?
A. Time to replace worn components
B. Time to write new logic
C. Time between physical maintenance checks
D. Time for one full execution cycle of the CPU
Scan time refers to how long it takes for a PLC to read inputs, process
logic, and update outputs.
7. Which file type is commonly used to store PLC program logic on a PC?
A. .docx
B. .jpg
C. .prg
D. .mp3
A .prg or similar extension is used for PLC programs in many software
environments.
8. What is the purpose of a PLC’s watchdog timer?
A. Increase output voltage
B. Log operator actions
C. Predict hardware failures
D. Detect program or hardware faults
A watchdog timer resets the PLC if it stops functioning normally.
9. A PLC’s discrete input module typically reads signals of what type?
A. Analog voltage
B. RF signals
, C. Light intensity
D. On/Off digital signals
Discrete input modules detect binary states such as switches or
contact closures.
10. Which device converts analog signals into digital values for a
PLC?
A. Transformer
B. Motor
C. Encoder
D. Analog-to-digital converter (ADC)
An ADC is used to translate real-world analog values into digital data
for the PLC.
11. In ladder logic, a coil represents what?
A. A transistor
B. A timer only
C. An output or internal bit
D. A power supply
A coil energizes an output or sets an internal relay bit based on logic
conditions.
12. Which PLC memory area stores the user program?
A. Backup battery
B. Display buffer
C. Network cache
D. Program memory
Program memory holds the user’s control logic instructions.
13. What’s the function of a PLC timer TON?
A. Count items
B. Convert inputs
C. Delay turning on outputs after input becomes true
D. Measure frequency
TON (Timer On Delay) delays activation of an output once conditions
are met.
14. A PLC counter that increases on each signal is called:
A. Down counter
B. Linear counter
