PLC TEST QUESTIONS AND ANSWERS
If all the units are in one fixed enclosure, the PLC is called a _______ PLC - Answers-
fixed
The four major components of a PLC power supply are a line conditioner or varistor,
transformer/rectifier unit, RC filter, and _______ - Answers- fixed plc
A(n) ________ is a semiconductor device that can maintain a steady voltage level -
Answers- zener diode
The section of the PLC system memory that holds the status of discrete input ports is
the ______ status - Answers- input
A ______ converts the digital output signals back to analog signals - Answers- digital-
to-analog converter
The _______ segments holds the ladder logic program - Answers- user memory
T or F. One benefit of PLCs over electromechanical relay logic systems is PLCs require
minor wiring and can be modified and reprogrammed within a few hours - Answers-
true
T or F. Discrete input ports are ports that are either open (off) or closed (on) - Answers-
true
T or F. Static RAM (SRAM) stores data in the form of charge on capacitors - Answers-
false
T or F. Read only memory (ROM) holds the permanent system programs - Answers-
true
T or F. The user memory segment stores information needed to execute the user
program - Answers- false
T or F. Simplex channeling occurs when the DTE either transmits data to or receives
data from the DCE - Answers- true
T or F. In half duplex channeling, the DTE trasmits data to and receives data from the
DCE through two seperate transmission lines - Answers- false
T or F. Sourcing occurs when the current flows out of the PLC port and sinking occurs
when the current flows into the PLC port - Answers- true
T or F. The arithmetic logic unit (ALU) carries out math and logic instructions - Answers-
true
If all the units are in one fixed enclosure, the PLC is called a _______ PLC - Answers-
fixed
The four major components of a PLC power supply are a line conditioner or varistor,
transformer/rectifier unit, RC filter, and _______ - Answers- fixed plc
A(n) ________ is a semiconductor device that can maintain a steady voltage level -
Answers- zener diode
The section of the PLC system memory that holds the status of discrete input ports is
the ______ status - Answers- input
A ______ converts the digital output signals back to analog signals - Answers- digital-
to-analog converter
The _______ segments holds the ladder logic program - Answers- user memory
T or F. One benefit of PLCs over electromechanical relay logic systems is PLCs require
minor wiring and can be modified and reprogrammed within a few hours - Answers-
true
T or F. Discrete input ports are ports that are either open (off) or closed (on) - Answers-
true
T or F. Static RAM (SRAM) stores data in the form of charge on capacitors - Answers-
false
T or F. Read only memory (ROM) holds the permanent system programs - Answers-
true
T or F. The user memory segment stores information needed to execute the user
program - Answers- false
T or F. Simplex channeling occurs when the DTE either transmits data to or receives
data from the DCE - Answers- true
T or F. In half duplex channeling, the DTE trasmits data to and receives data from the
DCE through two seperate transmission lines - Answers- false
T or F. Sourcing occurs when the current flows out of the PLC port and sinking occurs
when the current flows into the PLC port - Answers- true
T or F. The arithmetic logic unit (ALU) carries out math and logic instructions - Answers-
true
