Title: EIC225 Ch 2 Test Pool
Course: Open EIC225 Programmable Controllers

Q: An analog input or output is a signal that varies continuously within a certain range.
- True
- False
A: True

Q: Most input modules have blown fuse indicators.
- True
- False
A: False

Q: I/O modules are designed to plug into a slot or connector.
- True
- False
A: True

Q: Optical isolation used in I/O modules helps to reduce the effects of electrical noise.
- True
- False
A: True

Q: I/O modules are keyed to prevent unauthorized personnel from removing them from the I/O rack.
- True
- False
A: False

Q: The maximum current rating for the individual outputs of an AC output module is usually in the 20 to 30 ampere range.
- True
- False
A: False

Q: A thermocouple would be classified as an analog input sensing device.
- True
- False
A: True

Q: Shielded twisted pair cable is used for connecting to thermocouple inputs to reduce unwanted electrical noise.
- True
- False
A: True

Q: Electrical noise usually causes permanent operating errors.
- True
- False
A: False

Q: The processor may perform functions such as timing, counting, and comparing in addition to logic processing.
- True
- False
A: True

Q: Memory is where the control plan is held or stored in the controller.
- True
- False
A: True

Q: A volatile memory will lose its programmed contents if operating power is lost.
- True
- False
A: True

Q: A nonvolatile memory will retain its programmed contents if operating power is lost.
- True
- False
A: True

Q: RAM memory is nonvolatile.
- True
- False
A: False

Q: Information stored in a RAM memory location can be written into or read from.
- True
- False
A: True

Q: When a new program is loaded into a PLC's memory, the old program that was stored in the same locations is over-written and essentially erased.
- True
- False
A: True

Q: Most PLC programming software will allow you to develop programs on another manufacturer's PLC.
- True
- False
A: False

Q: Analog signals can have only two states.
- True
- False
A: False

Q: A modular PLC that has room for several I/O modules, is capable of being customized for a particular application.
- True
- False
A: True

Q: I/O modules are normally installed or removed while the PLC is powered.
- True
- False
A: False

Q: A module inserted into the wrong slot could be damaged.
- True
- False
A: True

Q: A redundant PLC system is configured using two processors.
- True
- False
A: True

Q: Most PLC electronic components are not sensitive to electrostatic discharge.
- True
- False
A: False

Q: One advantage of discrete relay contact output modules is that they can be used with AC or DC devices.
- True
- False
A: True

Q: If you had a hand-held programming terminal from one manufacturer you can program only that manufacture's PLC using it.
- True
- False
A: True

Q: Hot swappable I/O modules are designed to be changed with the power on and the PLC operating.
- True
- False
A: True

Q: HMI screens are developed using a software package on a PC which is downloaded into the PLC operator interface device.
- True
- False
A: True

Q: Discrete means that each input or output has two states: a. True (on) or b. False (off).
- True
- False
A: True

Q: Light is used in I/O modules to separate the real-world electrical signals from the PLC internal electronic system.
- True
- False
A: True

Q: Digital modules are also called discrete modules.
- True
- False
A: True

Q: The sum of the backplane current drawn for all modules in a chassis is used to select the appropriate chassis power supply rating.
- True
- False
A: True

Q: A ____ is an example of a device that could be used to provide a discrete input to a PLC.
- pushbutton
- selector switch
- limit switch
- all of these
A: all of these

Q: A ____ is an example of an actuator that could be controlled by a discrete output from a PLC.
- pushbutton
- motor starter
- limit switch
- all of these
A: motor starter

Q: A/An ____ input or output is a continuously variable signal within a designated range.
- discrete
- digital
- BCD
- analog
A: analog

Q: One function of a PLC input interface module is to:
- accept signals from field devices and convert them into signals that can be used by the processor.
- convert signals from the processing unit into values that can be used to control the machine or process.
- input signals from the programming device and convert them into signals that can be used by the CPU.
- interpret and execute the user program that controls the machine or process.
A: accept signals from field devices and convert them into signals that can be used by the processor.

Q: The location of a specific input or output field device is identified by the processor by means of its:
- voltage rating.
- current rating.
- wattage rating.
- address.
A: address.

Q: A discrete output interface module is designed to provide:
- output voltages only in the 5 VDC range.
- varying AC or DC voltages depending on the type of module selected.
- ON/OFF switching of the output field device.
- binary-coded outputs.
A: ON/OFF switching of the output field device.

Q: The following statement that does not apply to the optical isolator circuit used in I/O modules is that it:
- separates high voltage and low voltage circuits.
- rectifies AC signals.
- prevents damage caused by line voltage transients.
- reduces the effect of electrical noise.
A: rectifies AC signals.

Q: Individual outputs of a typical AC output interface module usually have a maximum current rating of about:
- 1 A or 2 A.
- 25 A or 50 A.
- 50 mA or 100 mA.
- 250 µA or 500 µA
A: 1 A or 2 A.

Q: Which of the following input field devices would most likely be used with an analog interface input module?
- Pushbutton
- Limit switch
- Selector switch
- Thermocouple
A: Thermocouple

Q: The "ON state input voltage range" specification refers to:
- the type of voltage device that will be accepted by the input.
- range of leakage voltage present at the input in its ON state.
- minimum and maximum output operating voltages.
- voltage at which the input signal is recognized as being ON.
A: voltage at which the input signal is recognized as being ON.

Q: Volatile memory elements can be classified as those that:
- do not retain stored information when the power is removed.
- retain stored information when the power is removed.
- do not require a battery backup.
- both b and c.
A: do not retain stored information when the power is removed.

Q: _____ memory is used by the PLC's operating system.
- RAM
- EEPROM
- Flash
- ROM
A: ROM

Q: _____ is a type of memory commonly used for temporary storage of data that may need to be quickly changed.
- RAM
- ROM
- EPROM
- EEPROM
A: RAM

Q: The most common form of memory used to store, back up, or transfer PLC programs is:
- RAM
- Flash EEPROM
- EEPROM
- both b and c
A: both b and c

Q: In event of a power interruption, a(an) _____ is used in some processors to provide power to the RAM.
- inductor
- capacitor
- transistor
- resistor
A: capacitor

Q: Which of the following is not a function of a PLC programming device?
- To enter the user program
- To change the user program
- To execute the user program
- To monitor the user program
A: To execute the user program

Q: Status indicators are provided on each output of an output module to indicate that the:
- load has been operated.
- input associated with the output is active.
- module fuse has blown.
- output is active.
A: output is active.

Q: The I/O system provides an interface between:
- input modules and output modules.
- the CPU and field equipment.
- the CPU and I/O rack.
- the I/O rack and I/O modules.
A: the CPU and field equipment.

Q: The PLC chassis comes in different sizes according to the:
- size of the program.
- type of I/O modules used.
- number of slots they contain.
- all of these.
A: number of slots they contain.

Q: The Allen-Bradley SLC-500 address I:2/4 refers to an:
- Input module in slot 4, terminal 2.
- Output module in slot 4, terminal 2.
- Input module in slot 2, terminal 4.
- Output module in slot 2, terminal 4.
A: Input module in slot 2, terminal 4.

Q: The Allen-Bradley SLC-500 address O:3/0 refers to an:
- Input module in slot 3, terminal 0.
- Output module in slot 3, terminal 0.
- Input module in slot 0, terminal 3.
- Output module in slot 0, terminal 3.
A: Output module in slot 3, terminal 0.

Q: For the I/O module shown, the arrows point to the:
- status indicator connections.
- input connections.
- output connections.
- power supply connections.
A: power supply connections.

Q: For the block diagram of the input module shown, Section #1 represents the ____ and #2 the ____
- AC, DC.
- DC, AC.
- power, logic.
- logic, power.
A: power, logic.

Q: The schematic diagram shown is that of a(n):
- discrete output module.
- analog output module.
- discrete input module.
- analog input module.
A: discrete input module.

Q: The purpose of the filter section is to:
- aid in fault diagnosis.
- set the minimum level of voltage that can be detected.
- protect against electrical noise interference.
- separate the higher line voltage from the logic circuits.
A: protect against electrical noise interference.

Q: The purpose of the zener diode (ZD) is to:
- aid in fault diagnosis.
- set the minimum level of voltage that can be detected.
- protect against electrical noise interference.
- separate the higher line voltage from the logic circuits.
A: set the minimum level of voltage that can be detected.

Q: The purpose of the LED indicator is to:
- aid in fault diagnosis.
- set the minimum level of voltage that can be detected.
- protect against electrical noise interference.
- separate the higher line voltage from the logic circuits.
A: aid in fault diagnosis.

Q: The purpose of the optical isolator is to:
- aid in fault diagnosis.
- set the minimum level of voltage that can be detected.
- protect against electrical noise interference.
- separate the higher line voltage from the logic circuits.
A: separate the higher line voltage from the logic circuits.

Q: For the block diagram of the output module shown, the input comes from the:
- input field device.
- processor.
- output field device.
- line power supply.
A: processor.

Q: The schematic diagram shown is that of a(n):
- discrete output module.
- analog output module.
- discrete input module.
- analog input module.
A: discrete output module.

Q: The input signal to the module comes from:
- the input field device.
- the output field device.
- internal logic circuitry of the processor.
- either a or b.
A: internal logic circuitry of the processor.

Q: The purpose of the triac switch is to:
- turn the load ON and OFF.
- vary the current flow to the load in accordance with the input signal level.
- vary the voltage across the load in accordance with the input signal level.
- both b and c.
A: turn the load ON and OFF.

Q: When the triac is in the OFF state:
- zero current always flows through the load.
- a small leakage current may flow through the load.
- the rated surge current flows through the lamp.
- the rated nominal current flows through the lamp.
A: a small leakage current may flow through the load.

Q: The schematic diagram of Figure 2-6 is an example of how a PLC output module is connected to:
- isolate the load from the controller.
- control a high resistance load.
- vary the speed of a motor.
- control a high current load.
A: control a high current load.

Q: Which of the following devices can be used for switching the output of a discrete DC output module?
- Transistor.
- Triac.
- Relay.
- either a or c.
A: either a or c.

Q: The current sourcing sensor shown must be matched with a _____ PLC input module.
- current sinking
- current sourcing
- alternating current
- either a or b
A: current sinking

Q: Typical analog inputs and outputs can vary from
- 0 to 20 mA
- 4 to 20 mA
- 0 to 10 volts
- All of these
A: All of these

Q: For the block diagram of the analog PLC control shown, which part has a binary input and analog output value?
- Level transmitter
- Input module
- Processor
- Output module
A: Output module

Q: For the thermocouple analog input module shown, shielded cable is used to:
- reduce unwanted electrical noise signals.
- carry the higher current required.
- lower the resistance of the conductors.
- insulate the circuit from other cables.
A: reduce unwanted electrical noise signals.

Q: The thermocouple shown is a:
- ungrounded type with the shield grounded at the module end.
- ungrounded type with the shield grounded at the thermocouple end.
- grounded type with the shield grounded at the module end.
- grounded type with the shield grounded at the thermocouple end.
A: ungrounded type with the shield grounded at the module end.

Q: The main element of an analog output module is:
- AC to DC rectifier.
- DC to AC inverter.
- analog to digital converter.
- digital to analog converter.
A: digital to analog converter.

Q: For the PLC analog I/O control system shown, the fluid flow is controlled by:
- varying the amount of the valve opening.
- switching the valve ON and OFF.
- switching the level sensor ON and OFF.
- varying the position of the level sensor.
A: varying the amount of the valve opening.

Q: Which of the following special I/O modules would be used to operate a seven-segment LED Display?
- Encoder-counter module.
- BCD-output module.
- Stepper-motor module.
- High-speed counter module.
A: BCD-output module.

Q: A ______ module is used to establish connections for the exchange of data.
- thumbwheel
- communication
- servo
- PID
A: communication

Q: High-density I/O modules:
- may have up to 64 inputs or outputs per module.
- require more space.
- can handle greater amounts of current per output.
- All of these.
A: may have up to 64 inputs or outputs per module.

Q: Discrete I/O modules can be classified as:
- bit oriented.
- word oriented.
- processor oriented.
- power supply oriented.
A: bit oriented.

Q: Which of the following specifications defines the number of field inputs or outputs that can be connected to a single module?
- Electrical isolation.
- Points per module.
- Threshold voltage.
- Current per input.
A: Points per module.

Q: The ____ of an analog I/O module specifies how accurately an analog value can be represented digitally.
- number of inputs and outputs per card
- input impedance and capacitance
- resolution
- common mode rejection ratio
A: resolution

Q: The processor module of the PLC is where the:
- ladder logic program is stored.
- input connections are made.
- output connections are made.
- sensors are located.
A: ladder logic program is stored.

Q: For the processor module shown, Block 1 represents the ___ and Block 2 the ___.
- input, output
- output, input
- memory, CPU
- CPU, memory
A: CPU, memory

Q: When placed in the ___mode, the processor does not scan/execute the ladder program.
- program
- run
- test
- remote
A: program

Q: The most commonly used programming device is a:
- personal computer.
- dedicated industrial programming terminal.
- hand-held programmer.
- proprietary programming device.
A: personal computer.

Q: Electronic components found in PLC modules:
- are not effected by electrostatic voltages.
- can be damaged by electrostatic voltages.
- can have their performance degraded by electrostatic voltages.
- both b and c.
A: both b and c.

Q: Batteries are used in a PLC's processor to:
- maintain data in volatile memory when line power is removed from the processor.
- operate the status lights LEDs.
- maintain data in nonvolatile memory when line power is removed from the processor.
- maintain outputs through a power failure.
A: maintain data in volatile memory when line power is removed from the processor.