Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

HET3 > 302Db: Off-Road Electrical Circuit Fundamentals > Flashcards

302Db: Off-Road Electrical Circuit Fundamentals Flashcards

1
Q

What is loop or ring topology relative to data bus configurations?

A

Early networks used a loop or ring topology in which all modules are wired in series.

One major disadvantage of the loop topology is that if one module on the bus lost power or ground, the whole network could lose communication.

302Db Pg. 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is star topology relative to data bus configurations?

A

A master module controls the data bus and the remaining modules are dependent slave modules.

This configuration allows the network to continue to communicate even when power or ground is lost to a module. Limited speed capability.

302Db Pg. 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is linear topology relative to data bus configurations?

A

Modern data bus configuration.
A main backbone with stubs running to each module. There is no master module. All modules receive all messages.

302Db Pg. 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is MID in a multiplexing message?

A

Message Identifier

One byte long and indicates the source address of the transmitting node

302Db Pg. 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is PID in a multiplexing message?

A

Parameter Identifier

One byte long. Indicates to what parameter the data corresponds.

302Db Pg. 8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does topology refer to in a data bus?

A

Describes a structure/arrangement of the control modules on the data bus.

Loop/Ring - Series configuration
Star - Master and multiple slave modules
Linear - Modern configuration with parallel connections

302Db Pg. 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The checksum comes before the final byte of data in a multiplexing message? (T/F)

A

False
Comes after the final byte of data

302Db Pg. 10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is one of the first tests you need to conduct with all multiplexed systems?

A

Determine if the system is receiving power.

302Db Pg. 22

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When testing multiplexed systems, we can use any multi meter. (T/F)

A

False
Failure to use a high impedance meter will result in damage to the electronic components.

302Db

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

SAE J1939-11 multiplexed systems run at what speeds?

A

250 kb/s

302Db Pg. 18

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the difference between shielded and unsheilded J1939?

A

J1939-11 Heavy:
- Max 30 nodes
- CAN High - Yellow
- CAN Low - Green
- Drain - Copper wire
- Shielded

J1939-15 Light:
- Max 10 nodes
- CAN High - Yellow
- CAN Low - Green

302Db Pg. 18

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Terminating resisters are used at each end of a multiplexing wire to prevent:

A

Standing waves

302Db Pg. 19

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which of the following best describes multiplexing?

a) Ability to communicate analog signals between communication devices
b) Ability to send and receive digital electronic signals over a pair of wires
c) Ability to increase the amount of wires necessary to connect inputs andoutputs
d) Ability to control devices wirelessly

A

B) The ability to send and receive digital electronic signals over a pair of wires

302Db Pg. 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does multiplexing reduce the number of conductors used on heavy equipment?

a) Eliminating redundant outputs
b) Reducing the number of control modules
c) Using larger conductor gauges
d) Allowing control modules to share data for inputs

A

D) Allowing control modules to share data for inputs

302Db

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which of the following is the measurement of data transfer speed over a network?

a) protocol
b) baud rate
c) data link
d) backbone

A

B) Baud rate

302Db Pg. 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the baud rate of J1939?

A

250 kb/s

302Db Pg. 5

17
Q

Which of the following is the communication language used between control modules?

a) protocol
b) baud rate
c) data link
d) back bone

A

A) Protocol

Set by SAE (Society of Automotive Engineers)

302Db Pg. 5

18
Q

How do you reduce interference of data in a multiplex data bus?

A

By using twisted wire pairs, drain wire, and shielding.

  • Reduces effects of magnetic fields
  • Maintains a constant capacitance

302Db Pg. 6

19
Q

Which data bus topology is typical for most modern mobile equipment units?

A

Linear

302Db Pg. 7

20
Q

Which of the following terminates and validates the message communicated over a J1587/J1708 data link?

a) message identifier (MID)
b) parameter identifier (PID)
c) parameter data bytes
d) checksum

A

D) Checksum

302Db Pg. 10

21
Q

What is the color code for the older J1587/J1708 twisted wire pair?

A

Orange and White

  • Does not require terminating resistors
  • Gold plated pins
  • Unshielded
  • 6 pin connector
  • 9.6 kb/s

302Db Pg. 10

22
Q

In a J1939 message, which of the following replaces the parameter identifier (PID) that was previously used in the J1587/J1708 protocol?

a) parameter group number (PGN)
b) suspect parameter number (SPN)
c) failure mode identifier (FMI)
d) arbitration field

A

B) Suspect parameter number (SPN)

Identifies and reports where a failure has occured. Range from 0 to 520191.
Six digit SPN instead of the older three digit PID

302Db Pg. 15

23
Q

Which of the following best describes the construction of the J1939-11 heavy cable?

a) unshielded twisted pair
b) shielded twisted pair
c) unshielded twisted quad
d) shielded twisted quad

A

B) Shielded twisted pair

302Db Pg. 18

24
Q

What is the drain wire connected to in a shielded twisted pair?

A

Battery ground

302Db

25
Q

Identify and explain the two reasons why data links are twisted.

A
  • Reduce effects of magnetic interferance
  • Help maintain constant capacitance

302Db Pg. 6

26
Q

What is the purpose of the terminating resistors?

A

To minimize the occurrence of standing waves

302Db Pg. 19

27
Q

When performing the CAN data wire ground fault test, which of the following is the expected reading of a properly functioning system?

a) Less than 60Ω
b) 60Ω
c) 1 MΩ - 4 MΩ
d) 240Ω

A

C) 1 MΩ – 4 MΩ

Measuring From:
CAN-High to Ground
CAN-Low to Ground

302Db Pg. 24

28
Q

When performing the terminating resistor test on a J1939 data link, what does a reading of less than 60 Ω indicate?

a) No fault
b) Ground fault
c) Open
d) Short

A

D) Short

302Db Pg. 25

29
Q

Which of the following best describes the construction of the ISO11783 cable?

a) unshielded twisted pair
b) shielded twisted pair
c) unshielded twisted quad
d) shielded twisted quad

A

C) Unshielded twisted quad

302Db Pg. 26

30
Q

Explain the two functions the terminating bias circuit performs on the ISO11783 data link.

A

The terminating bias circuit uses dedicated battery power and ground supply along with the CAN-High and CAN-Low signal to provide electrical bias and termination to the network, preventing reflections from occurring in the system that would create interference.

302Db Pg. 27

31
Q

Which of the following best describes the function of the ISO11783 tractor breakaway connector?

a) to allow machine manufacturers to have their machines connect to their implements only
b) to allow any machine to connect to any implement
c) to allow machine manufacturers proprietary access to implements
d) to decrease the versatility of machine and implement combinations

A

B) To allow any machine to connect to any implement

302Db Pg. 28

HET3 (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions