South Carolina PLC Programmer
Technician Certification License Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. In a PLC program, what is the primary purpose of a ladder logic rung?
A. To store data values in memory
B. To execute arithmetic calculations
C. To represent a specific control operation
D. To configure hardware modules
A ladder logic rung visually represents a control operation, allowing
the PLC to evaluate conditions and execute outputs based on input
states.
2. Which of the following PLC scan cycle steps occurs first?
A. Output update
B. Input scan
C. Program execution
D. Diagnostic checks
The input scan is the initial step in a PLC scan cycle, during which the
PLC reads and updates the status of all input devices.
3. In PLC addressing, what does the label I:1/03 typically represent?
A. Output 3 on rack 1
, B. Input 3 on rack 1
C. Internal bit 3
D. Timer bit 3
The format I:1/03 denotes the third input bit on input module slot 1
in the PLC rack.
4. Which function block is used to delay turning on an output once its
input condition becomes true?
A. RETENTIVE Timer
B. Counter Up
C. On-Delay Timer (TON)
D. Pulse Generator
The On-Delay Timer (TON) waits a specified time after an input
condition becomes true before energizing its output.
5. Which type of PLC memory is used to retain values even when power
is lost?
A. RAM
B. EEPROM
C. Volatile cache
D. Scratchpad
EEPROM is nonvolatile memory that stores critical PLC program data
that must be preserved through power cycles.
6. What does the ladder instruction “OTE” stand for?
A. Output Toggle Enable
B. Output Energize
C. Output Timer Event
D. Operational Test Engine
OTE is used to energize or de-energize an output when the logic on
the rung is true.
, 7. A MOV instruction in PLC logic is used to:
A. Compare two values
B. Transfer data from one location to another
C. Multiply numeric values
D. Reset counters
MOV moves a source value into a destination address without
altering the source.
8. What is the main purpose of a retentive counter?
A. Store boolean flags
B. Measure elapsed time
C. Delay input signals
D. Count events and retain the count through power cycles
Retentive counters accumulate counts and maintain the total even
after a PLC power loss.
9. A high-speed counter (HSC) is typically used for:
A. Analog signal conversion
B. Counting fast pulses from encoders
C. Timer sequencing
D. Displaying values on HMI
High-speed counters are specialized to rapidly count pulses from
high-frequency inputs such as encoders.
10. In PLC terminology, an input filter is used to:
A. Increase output speed
B. Convert analog to digital signals
C. Debounce noisy input signals
D. Prevent memory overwrite
Input filters stabilize noisy signals by ignoring rapid, unintended
fluctuations from mechanical switches.
Technician Certification License Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. In a PLC program, what is the primary purpose of a ladder logic rung?
A. To store data values in memory
B. To execute arithmetic calculations
C. To represent a specific control operation
D. To configure hardware modules
A ladder logic rung visually represents a control operation, allowing
the PLC to evaluate conditions and execute outputs based on input
states.
2. Which of the following PLC scan cycle steps occurs first?
A. Output update
B. Input scan
C. Program execution
D. Diagnostic checks
The input scan is the initial step in a PLC scan cycle, during which the
PLC reads and updates the status of all input devices.
3. In PLC addressing, what does the label I:1/03 typically represent?
A. Output 3 on rack 1
, B. Input 3 on rack 1
C. Internal bit 3
D. Timer bit 3
The format I:1/03 denotes the third input bit on input module slot 1
in the PLC rack.
4. Which function block is used to delay turning on an output once its
input condition becomes true?
A. RETENTIVE Timer
B. Counter Up
C. On-Delay Timer (TON)
D. Pulse Generator
The On-Delay Timer (TON) waits a specified time after an input
condition becomes true before energizing its output.
5. Which type of PLC memory is used to retain values even when power
is lost?
A. RAM
B. EEPROM
C. Volatile cache
D. Scratchpad
EEPROM is nonvolatile memory that stores critical PLC program data
that must be preserved through power cycles.
6. What does the ladder instruction “OTE” stand for?
A. Output Toggle Enable
B. Output Energize
C. Output Timer Event
D. Operational Test Engine
OTE is used to energize or de-energize an output when the logic on
the rung is true.
, 7. A MOV instruction in PLC logic is used to:
A. Compare two values
B. Transfer data from one location to another
C. Multiply numeric values
D. Reset counters
MOV moves a source value into a destination address without
altering the source.
8. What is the main purpose of a retentive counter?
A. Store boolean flags
B. Measure elapsed time
C. Delay input signals
D. Count events and retain the count through power cycles
Retentive counters accumulate counts and maintain the total even
after a PLC power loss.
9. A high-speed counter (HSC) is typically used for:
A. Analog signal conversion
B. Counting fast pulses from encoders
C. Timer sequencing
D. Displaying values on HMI
High-speed counters are specialized to rapidly count pulses from
high-frequency inputs such as encoders.
10. In PLC terminology, an input filter is used to:
A. Increase output speed
B. Convert analog to digital signals
C. Debounce noisy input signals
D. Prevent memory overwrite
Input filters stabilize noisy signals by ignoring rapid, unintended
fluctuations from mechanical switches.
