SIEMENS LEVEL 1 CERTIFICATION | QUESTIONS AND ANSWERS | 2026 UPDATE |
WITH COMPLETE SOLUTION.
Question 1
Memory Coil instructions look and operate just like Assignment instructions, except they use an
__________ memory address instead of an output address.
A) External
B) Internal
C) Global
D) Physical
E) Hard-wired
Correct Answer: B) Internal
Rationale: Memory Coils (often referred to as M-bits or Merkers) are internal bits used to
store the status of logic operations within the PLC's memory. Unlike output addresses (Q),
they do not directly control physical hardware devices.
Question 2
N.O. and N.C. contact instructions can be controlled by __________ instructions simply by
giving the contacts the address of the instruction.
A) Timer
B) Counter
C) Assignment
D) Math
E) Jump
Correct Answer: C) Assignment
Rationale: In PLC programming, an Assignment instruction (the coil) sets the state of a bit.
Any Normally Open (N.O.) or Normally Closed (N.C.) contact sharing that same bit
address will respond immediately to the status set by that Assignment instruction.
Question 3
PLC seal-in logic works by using an N.O. contact instruction that is connected in __________
with the instruction which turns on the output.
A) Series
B) Parallel
C) Tandem
D) Reverse
E) Sequence
Correct Answer: B) Parallel
Rationale: A seal-in (or latch) circuit requires an N.O. contact of the output to be wired in
parallel with the momentary "Start" input. This ensures that once the output is energized,
it provides its own path for current even after the start button is released.
, 2
Question 4
What is the standard time base for a Siemens S7-1200 PLC timer?
A) Seconds only
B) Milliseconds only
C) Minutes only
D) All of these are appropriate time bases (ms to days)
E) 1.0 seconds only
Correct Answer: D) All of these are appropriate time bases (ms to days)
Rationale: Siemens S7-1200 timers (IEC Timers) utilize a TIME data type. This allows the
user to specify duration in milliseconds, seconds, minutes, hours, and even days using the
format T#2d10h30m5s10ms.
Question 5
Which of the following data bits in a Siemens S7-1200 Count Down (CTD) Data Block indicates
that the current count value is less than or equal to zero?
A) CD
B) LD
C) QD
D) PV
E) CV
Correct Answer: C) QD
Rationale: In a CTD instruction, QD is the "Status" output. It becomes True when the
Current Value (CV) is less than or equal to zero, signaling that the countdown is complete.
Question 6
The Siemens S7-1200 Count Up (CTU) instruction increases its __________ by one each time
its Count Up (CU) input is turned on.
A) Preset Value (PV)
B) Status Output (Q)
C) Reset Value (R)
D) Count Value (CV)
E) Data Block Number
Correct Answer: D) Count Value (CV)
Rationale: The Count Value (CV) is the internal register that tracks the current tally. Every
rising edge (transition from False to True) on the CU input increments this value.
Question 7
Siemens S7-1200 projects are developed using four types of blocks: Organizational blocks (OB),
Functions (FC), Function Blocks (FB), and __________.
A) Logic Blocks
B) Hardware Blocks
, 3
C) Data Blocks (DB)
D) Monitor Blocks
E) Timer Blocks
Correct Answer: C) Data Blocks (DB)
Rationale: Data Blocks are used to store global or instance-specific data that can be accessed
by various parts of the program. They are essential for memory management in Siemens S7
architectures.
Question 8
Startup organization blocks (OB100) execute once when the PLC transitions from __________.
A) Run to Stop mode
B) Stop to Run mode
C) Run to Error mode
D) Offline to Online
E) Start to Finish
Correct Answer: B) Stop to Run mode
Rationale: The Startup OB (usually OB100) is a special organization block that runs exactly
once during the PLC's initialization phase (transitioning to Run mode). It is typically used
to reset variables or initialize hardware settings.
Question 9
To associate HMI screen elements with data in the PLC, which of the following must be used?
A) HMI Cables
B) PLC IP Addresses
C) HMI Tags
D) Screen Indicators
E) C++ Scripts
Correct Answer: C) HMI Tags
Rationale: HMI Tags act as the communication link. They are mapped to specific PLC
addresses (Tags). When an HMI element is linked to an HMI Tag, it can read from or write
to the corresponding PLC memory location.
Question 10
Data is exchanged between the PLC and the HMI via _______.
A) Pins
B) Coils
C) Tags
D) Labels
E) Contacts
Correct Answer: C) Tags
Rationale: Tags are the standardized way Siemens software (TIA Portal) manages variables.
WITH COMPLETE SOLUTION.
Question 1
Memory Coil instructions look and operate just like Assignment instructions, except they use an
__________ memory address instead of an output address.
A) External
B) Internal
C) Global
D) Physical
E) Hard-wired
Correct Answer: B) Internal
Rationale: Memory Coils (often referred to as M-bits or Merkers) are internal bits used to
store the status of logic operations within the PLC's memory. Unlike output addresses (Q),
they do not directly control physical hardware devices.
Question 2
N.O. and N.C. contact instructions can be controlled by __________ instructions simply by
giving the contacts the address of the instruction.
A) Timer
B) Counter
C) Assignment
D) Math
E) Jump
Correct Answer: C) Assignment
Rationale: In PLC programming, an Assignment instruction (the coil) sets the state of a bit.
Any Normally Open (N.O.) or Normally Closed (N.C.) contact sharing that same bit
address will respond immediately to the status set by that Assignment instruction.
Question 3
PLC seal-in logic works by using an N.O. contact instruction that is connected in __________
with the instruction which turns on the output.
A) Series
B) Parallel
C) Tandem
D) Reverse
E) Sequence
Correct Answer: B) Parallel
Rationale: A seal-in (or latch) circuit requires an N.O. contact of the output to be wired in
parallel with the momentary "Start" input. This ensures that once the output is energized,
it provides its own path for current even after the start button is released.
, 2
Question 4
What is the standard time base for a Siemens S7-1200 PLC timer?
A) Seconds only
B) Milliseconds only
C) Minutes only
D) All of these are appropriate time bases (ms to days)
E) 1.0 seconds only
Correct Answer: D) All of these are appropriate time bases (ms to days)
Rationale: Siemens S7-1200 timers (IEC Timers) utilize a TIME data type. This allows the
user to specify duration in milliseconds, seconds, minutes, hours, and even days using the
format T#2d10h30m5s10ms.
Question 5
Which of the following data bits in a Siemens S7-1200 Count Down (CTD) Data Block indicates
that the current count value is less than or equal to zero?
A) CD
B) LD
C) QD
D) PV
E) CV
Correct Answer: C) QD
Rationale: In a CTD instruction, QD is the "Status" output. It becomes True when the
Current Value (CV) is less than or equal to zero, signaling that the countdown is complete.
Question 6
The Siemens S7-1200 Count Up (CTU) instruction increases its __________ by one each time
its Count Up (CU) input is turned on.
A) Preset Value (PV)
B) Status Output (Q)
C) Reset Value (R)
D) Count Value (CV)
E) Data Block Number
Correct Answer: D) Count Value (CV)
Rationale: The Count Value (CV) is the internal register that tracks the current tally. Every
rising edge (transition from False to True) on the CU input increments this value.
Question 7
Siemens S7-1200 projects are developed using four types of blocks: Organizational blocks (OB),
Functions (FC), Function Blocks (FB), and __________.
A) Logic Blocks
B) Hardware Blocks
, 3
C) Data Blocks (DB)
D) Monitor Blocks
E) Timer Blocks
Correct Answer: C) Data Blocks (DB)
Rationale: Data Blocks are used to store global or instance-specific data that can be accessed
by various parts of the program. They are essential for memory management in Siemens S7
architectures.
Question 8
Startup organization blocks (OB100) execute once when the PLC transitions from __________.
A) Run to Stop mode
B) Stop to Run mode
C) Run to Error mode
D) Offline to Online
E) Start to Finish
Correct Answer: B) Stop to Run mode
Rationale: The Startup OB (usually OB100) is a special organization block that runs exactly
once during the PLC's initialization phase (transitioning to Run mode). It is typically used
to reset variables or initialize hardware settings.
Question 9
To associate HMI screen elements with data in the PLC, which of the following must be used?
A) HMI Cables
B) PLC IP Addresses
C) HMI Tags
D) Screen Indicators
E) C++ Scripts
Correct Answer: C) HMI Tags
Rationale: HMI Tags act as the communication link. They are mapped to specific PLC
addresses (Tags). When an HMI element is linked to an HMI Tag, it can read from or write
to the corresponding PLC memory location.
Question 10
Data is exchanged between the PLC and the HMI via _______.
A) Pins
B) Coils
C) Tags
D) Labels
E) Contacts
Correct Answer: C) Tags
Rationale: Tags are the standardized way Siemens software (TIA Portal) manages variables.
