Title: Module 2 Test
Course: Open EIC225 Programmable Controllers

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

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

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

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

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.

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

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

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

Q: Information stored in a RAM memory location can be written into or read from.
- 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: 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: Memory is where the control plan is held or stored in the controller.
- True
- False
A: True

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

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

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

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

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

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

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: 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: All digital computing devices perform operations in binary.
- True
- False
A: True

Q: All digital computing devices operate using the binary number system because:
- most people are familiar with it.
- large decimal numbers can be represented in a shorter form.
- digital circuits can be easily distinguished between two voltage levels.
- all of the above.
A: digital circuits can be easily distinguished between two voltage levels.

Q: A(n) ___________ bit is used to detect errors that may occur while a word is moved.
- parity
- negative
- positive
- overflow
 
A: parity

Q: Binary number systems use positive and negative symbols to represent the polarity of a number.
- True
- False
A: False

Q: For a base 8 number system, the weight value associated with the third digit would be:
- 16.
- 32.
- 64.
- 512.
A: 64.

Q: If a given memory unit consists of 1250 16-bit words, the memory capacity would be rated:
- 1250 bits.
- 20,000 bits.
- 3260 bits.
- 156 bits.
A: 20,000 bits.

Q: In any number system, the position of a digit that represents part of the number has a weighted value associated with it.
- True
- False
A: True

Q: In any number system, the position of a digit that represents part of the number has a "weight" associated with its value. The place weights for binary:
- start with 1 and are successive powers of 2.
- increase by adding 2 for each place, starting with 0.
- increase by adding 2 for each place, starting with 2.
- start with 2 and double for each successive place.
A: start with 1 and are successive powers of 2.

Q: In the Gray code there is a maximum of one bit change between two consecutive numbers.
- True
- False
A: True

Q: In the sign bit position, a 1 indicates a(n):
- negative number.
- positive number.
- octal code.
- hexadecimal code.

 
A: negative number.

Q: One byte of the data shown is represented by:
- No. 1
- No. 2
- No. 3
- No. 4

 
A: No. 1

Q: The 2's complement form of a binary number is the binary number that results when:
- all the l's are changed to 0's.
- all the 0's are changed to 1's.
- 1 is added to the 1's complement.
- both a and b
A: 1 is added to the 1's complement.

Q: The acronym BCD stands for:
- binary-coded decimal.
- binary code decoder.
- base code decoder.
- base-coded decimal.
A: binary-coded decimal.

Q: The ASCII code:
- is used with absolute encoders.
- is considered to be an error-minimizing code.
- includes letters as well as numbers.
- all of these.
A: includes letters as well as numbers.

Q: The base of a number system determines the total number of unique symbols used by that system.
- True
- False
A: True

Q: The binary number 101 has the decimal equivalent of:
- 3.
- 101.
- 41.
- 5.
A: 5.

Q: The binary number 101101 would be written in decimal as:
- 21.
- 36.
- 45.
- 62.
A: 45.

Q: The decimal number 15 would be written in binary as:
- 1111.
- 1000.
- 4C.
- 00011001.
A: 1111.

Q: The decimal number 28 would be written in binary as:
- 11100.
- 00111.
- 10110.
- 01011.
A: 11100.

Q: The decimal number 213 would be written in BCD as:
- 0010 0001 0011.
- 1101 1000 1100.
- 0111 1001 0011.
- 1011 1101 0101.
A: 0010 0001 0011.

Q: The decimal system has as its base:
- 2.
- 5.
- 8.
- 10.
A: 10.

Q: The decimal system uses the number 9 as its base.
- True
- False
A: False

Q: The hexadecimal number system consists of 16 digits including the numbers 0 through 9 and letters A through F.
- True
- False
A: True

Q: The hexadecimal number C4 would be written in decimal as:
- 21
- 48
- 182
- 196

 
A: 196

 

Q: The hexadecimal number 2D9 would be written in binary as:
- 0010 1101 1001.
- 1001 1011 0010.
- 1100 1111 0010.
- 0010 1011 1001.
A: 0010 1101 1001.

Q: The main advantage of using the Gray code is:
- only one digit changes as the number increases.
- it can be easily converted to decimal numbers.
- large decimal numbers can be written using fewer digits.
- it uses the number 2 as its base.

 
A: only one digit changes as the number increases.

Q: The memory size represented is:
- 1023 K
- 1000 K
- 500 K
- 1 K
A: 1 K

Q: The MSB of the data shown in Figure 3-1 is represented by:
- No. 1
- No. 2
- No. 3
- No. 4

 
A: No. 2

Q: The number 127 could not be:
- decimal.
- hexadecimal.
- octal.
- binary.

 
A: binary.

 

Q: The number 12 is:
- 12 in any number system.
- 12 in decimal.
- 12 in binary.
- all of the above.
A: 12 in decimal.

Q: The octal number 153 would be written in binary as:
- 011 101 001.
- 001 101 011.
- 011 111 101.
- 010 100 011.
A: 001 101 011.

Q: The octal number 62 would be written in decimal as:
- A12.
- F35.
- 50.
- 98.
A: 50.

Q: The octal number system consists of digits 0, 1, 2, 3, 4, 5, 6, and 7. There are no 8's or 9's.
- True
- False
A: True

Q: The radix of a number system is the same as the base.
- True
- False
A: True

Q: To express a number in binary requires fewer digits than in the decimal system.
- True
- False
A: False

Q: Usually a group of 8 bits is a byte, and a group of one or more bytes is a word.
- True
- False
A: True

Q: Which of the following number systems has a base of 16?
- Hexadecimal
- Octal
- Binary-coded decimal
- Gray code

 
A: Hexadecimal

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: 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 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.