Deck 7: Embedded Microcontrollers, Open and Closed Loop Process Control

Question 1

Both a microcomputer and a microcontroller contain a CPU.

Answer 1

True

Question 2

An 8 -bit CPU has an address bus that is eight bits wide.

Answer 2

False

Question 3

The content of a ROM is sometimes called firmware because it contains the program.

Answer 3

False

Question 4

An EPROM uses ultraviolet light to erase its contents.

Question 5

Parallel I/O is referred to as GPIO.

Question 6

Both synchronous and asynchronous ports provide serial I/O for the microcontroller.

Question 7

The synchronous communication port on a microcontroller is used for servicing and testing.

Question 8

The three main bus systems in a microcontroller are address, data, and I/O.

Question 9

A RISC CPU has less instructions available to the programmer than a non -RISC CPU.

Question 10

A watchdog timer generates an interrupt when the system is hung.

Question 11

The Joint Test Action Group coordinates those microcontroller instructions that are used for software troubleshooting.

Question 12

A USART is a universal synchronous and real time transmitter.

Question 13

A SRAM is a static random access memory.

Question 14

Assembly language is a low -level language that uses mnemonic instructions.

Question 15

When compiling your high level language program, an assembler is still required to translate to machine language.

Question 16

Build process errors result from misinterpretation of requirements.

Question 17

A source -code debugger controls the program on the target system.

Question 18

The disadvantage of simulators is that they cannot simulate I/O signals.

Question 19

In -circuit emulators provide a quick, accurate and inexpensive method of debugging.

Question 20

The program for a BASIC stamp is compressed and download from a PC.

Question 21

Match the type of code t o its name.

-Subroutine

A) Routine
B) Code used by the MCU
C) Group of routines
D) Code generated by the programmer

Question 22

Match the type of code t o its name.

-Function

A) Routine
B) Code used by the MCU
C) Group of routines
D) Code generated by the programmer

Question 23

Match the type of code t o its name.

-Module

A) Routine
B) Code used by the MCU
C) Group of routines
D) Code generated by the programmer

Question 24

Match the type of code t o its name.

-Object

A) Routine
B) Code used by the MCU
C) Group of routines
D) Code generated by the programmer

Question 25

Match the type of code t o its name.

-Source

A) Routine
B) Code used by the MCU
C) Group of routines
D) Code generated by the programmer

Question 26

March the feature to its language.

-Precise control of the CPU

A) Assembly language
B) C languag

Question 27

March the feature to its language.

-Independent of CPU

A) Assembly language
B) C languag

Question 28

March the feature to its language.

-Cannot access all CPU instructions

A) Assembly language
B) C languag

Question 29

March the feature to its language.

-Program structure

A) Assembly language
B) C languag

Question 30

March the feature to its language.

-Simple development

A) Assembly language
B) C languag

Question 31

Automatic control is a system where a process variable is forced to remain at a desired value called the controller output point.

Question 32

One of the four advantages provided by a control system is compensation for disturbances.

Question 33

Dead time delay is the time delay between the start of the transient response and the time that steady state response starts.

Question 34

The transient response time for a control system is the length of time between the start of the rise or fall in the process variable and the point where it reaches the maximum change.

Question 35

Steady state error is the value of the error signal or the offset in the process variable after the control system has responded to a change and settled down to its final value.

Question 36

The system response is the change in the system output when a known stimulus, such as a step function, is applied to the system input.

Question 37

A system model is a mathematic description of the system that generates the same transient and steady -state output response to a known input stimulus as the actual system.

Question 38

Gain for a process control system or block is the change in input value divided by the change in output value.

Question 39

Modeling of the production process is more often done with process systems that have been in operation for a number of years because much is known about the systems.

Question 40

Open loop systems do not have feedback but are self regulating.

Question 41

Controller gain is known and predictable, but process gain is often difficult to establish and may not be constant or linear.

Question 42

The error equation for a direct acting closed loop system is E=SP -PV.

Question 43

In a reverse acting closed loop control system, the process variable and the controller output move in the same direction.

Question 44

A process load change is a change in the process environment that causes the process to move away from the set point value.

Question 45

Of the three components in a system response (dead time, transient response, and steady -state response), dead time is the most difficut for the closed -loop system to correct.

Question 46

The damping coeficient value for an overdamped response is a number less than 0.5.

Question 47

If the control system is underdamped then the response for the control system has ringing.

Question 48

There are three distinct types of response curves: underdamped, critically damped, and overdamped.

Question 49

The damping coefficient is a number between 0 and 2.

Question 50

A bias value can be used to correct for steady -state error, but the bias value must be changed whenever the set point is changed or a new disturbance is present.

Question 51

The total system response is the sum of the natural and forced responses.

Question 52

The forced system response is what a system does after a disturbance or set point change and dies out to 0 or a steady oscillation if the system is stable.

Question 53

Phase margin is the addition drop in phase angle from 180 degrees that makes a system more responsive but not unstable.

Question 54

The peak gain on the closed loop Bode response for a second order lag system should be between 8 and 10 db.

Question 55

The on -off controller's output is either 0 or 100 percent on either side of the zero error value.

Question 56

Two -position controllers do not have output hystersis but on -off types have output hystersis.

Question 57

The dead band in a two -position controller causes the outputs to change when input error is at plus one -half of the dead band and at minus one -half of the dead band.

Question 58

Floating control has three output levels of 0, 50, and 100 percent.

Question 59

Single loop continuous controllers are limited to the following operation modes: P, I, D, PI, PID.

Question 60

PWM is one type of controller output; the other is gain -error product.

Question 61

Proportional gain is the change in input over the change in output.

Question 62

Proportional band is the total range of the error signal that causes the final control element to go through its full range.

Question 63

Control systems with only proportional control will always have a process variable offset after a disturbance to the system.

Question 64

The only way to eliminate steady -state error after a system disturbance is to add equal amounts of integral and derivative action to a proportional controller.

Question 65

Derivative action in a controller causes the final control element to change rapidly with rapid changes in the error.

Question 66

Integral time is the number of repeats per minute and reset is the reciprocal of the integral time.

Question 67

The integral time for an integral controller is the time required for the integral controller output to match the change produced by the proportional controller output.

Question 68

Analog derivative controllers have a capacitor in the feedback path and integral controllers have a capacitor in the input path of the amplifier.

Question 69

Digital controllers calculate the output at time intervals called processor recalculation time.

Question 70

Digital controllers take the change in the gain -error product from the last output calculation and add that to the last controller output for a new controller value.

Question 71

One difference between digital controller and analog controllers is that analog controllers produce an output almost instantly, while the digital output is based on the sampling rate.

Question 72

Fuzzy logic controllers are used on systems that are very complex and difficult to model.

Question 73

Fuzzy logic controllers use rules and reasoning principles similar to human problem solving in the solution of control problems.

Question 74

Feedforward control is used for systems with large time constants and with a disturbance in a system parameter that is controlled by the final control element.

Question 75

Cascade control is used when the important disturbance to control is not controlled by the final control element for the process variable.

Question 76

Ratio control is used when two liquids must be mixed in a precise proportion.

Question 77

If a square -root extractor is added to a control systems to linearize a process controller output then the controller is often called an adaptive controller.

Question 78

In cascade and feedforward control the control systems uses two closed -loop systems to correct for system disturbances.

Question 79

When a bump test is performed you get a process response curve that can be used to check proper tuning of a process variable.

Question 80

Process control systems have so much integration of technology that it is not possible to separate process problems from control problems.