Off Road Electrical System Fundamentals Part B Flashcards
Which of the following best describes multiplexing?
a. the ability to communicate analog signals between communication devices.
b. the ability to send and receive digital electronic signals over a pair of wires.
c. the ability to increase the amount of wires necessary to connect inputs and outputs.
d. the ability to control devices wirelessly.
b. the ability to send and recieve digital electronic signals over a pair of wires.
Which of the following is the measurement of data transfer speed over a network?
a. protocol
b. baud rate
c. data link
d. backbone
b. baud rate
Which of the following is the communication language used between control modules?
a. protocol
b. baud rate.
c. data link
d. back bone
a. protocol
Which topology is typical for most modern mobile equipment units?
a. loop
b. star
c. linear
d. hybrid
c. linear
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
d. checksum
Which of the following replaces the parameter identifier (PID) in a J1939 message?
a. parameter group number (PGN)
b. suspect parameter number (SPN)
c. failure mode identifier (FMI)
d. arbitration field
b. suspect parameter number (SPN)
What is the drain wire connected to in a shielded twisted pair?
a. battery ground.
b. battery positive
c. J1939 High
d. J1939 Low
a. battery ground
What is the purpose of terminating resistors?
a. to minimize the occurrence of standing waves.
b. to drop the data link voltage to spec.
c. to reduce the occurrence of large voltage spikes.
d. to hold the data link resistance at 240 ohms.
a. to minimize the occurrence of standing waves.
When performing the terminating resistor test on a J1939 data link, what does a reading of less than 60 ohms indicate?
a. no fault
b. ground fault
c. open
d. short
d. short
Explain the two functions the terminating bias circuit performs on the ISO11783 data link.
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 cause interference.
How does multiplexing reduce the number of conductors used on heavy equipment?
a. by eliminating redundant outputs.
b. by reducing the number of control modules
c. by using larger conductor gauges
d. by allowing control modules to share data for inputs.
d. by allowing control modules to share data for inputs.
What is the baud rate for J1939?
a. 10 kb/s
b. 10 bps
c. 250 kb/s
d. 250 bps
c. 250 kb/s
How do you reduce interference of data communication?
a. by using diodes and resistors in parallel to data link.
b. by using twisted wire pairs and drain wire shielding.
c. by using capacitors and resistors is series to data link.
d. by using capacitors and resistors in parallel to data link.
b. by using twisted wire pairs and drain wire shielding.
Explain serial communication over the CAN network.
In serial communications one bit is broadcasted after another in sequential order. Each controller contains a CAN transceiver chip that is designed to follow the CAN protocol. There is no master control device in a CAN network; each module knows which messages and modules have priority and must wait until the data bus is ready to start a broadcast.
What is the color code for J1587/J1708 twisted wire pair?
a. blue and white
b: green and blue
c. orange and white
d. green and yellow
c. orange and white
