5.4 Data Buses NEW

Question 1

Wiring utilized to transmit data caries only a negligible current, just sufficient to do what?

Answer 1

Switch a transistor ON or OFF or to carry an audio signal which is then amplified at its destination.

Question 2

What voltage levels are required for Binary 0?

Answer 2

0 to 0.8V

Question 3

What voltage levels are required for Binary 1?

Answer 3

2 to 5 Volts

Question 4

What are the 2 ways of data transfer between systems?

Answer 4

Parallel data transfer and Serial data transfer.

Question 5

In serial transfer the data is transferred over?

Answer 5

The same line in sequence.

Question 6

What triggers the transfer of data?

Answer 6

Clock pulses

Question 7

What is the typical method of speeding up s serial data bus?

Answer 7

Multiplexing

Question 8

In parallel transfer each bit is taken from?

Answer 8

A separate circuit and is transmitted over a separate line.

Question 9

What are the advantages of parallel transfer and Disadvantages.

Answer 9

Much faster. Disadvantage = much more hardware, more space and weight.

Question 10

What are the benefits of multiplexing?

Answer 10

Significant reduction in weight of wires and improved circuit reliability.

Question 11

How does multiplexing operate?

Answer 11

Via synchronized rotating contacts connecting matching input and output lines in sequence. Data transmitted over the common transmission line.

Question 12

In reality multiplexing is usually achieved by?

Answer 12

Logic gates responding in sequence to clock pulse signals.

Question 13

What is the purpose of the shielding on the twisted wire pair?

Answer 13

Spike protection, eliminates EMF, guarantee’s accurate transmissions

Question 14

What is the purpose of the twisted wire?

Answer 14

Magnetic fields induced by the currents flowing through them will cancel each out out, eliminating EMI

Question 15

All peripheral components are connected to the highway by?

Answer 15

Breakouts (Couplers)

Question 16

MIL-STD-1553 defines the term Tim division multiplexing as?

Answer 16

Transmission of information from several signal sources through the same line with different signal samples in time to form a composite pulse train.

Question 17

Q. What are the the 3 MIL-STD-1553 Data words?

Answer 17

Command words, Data Words, Status Words

Question 18

What is the length of word for a MIL-STD-1553

Answer 18

20 bits in length.

Question 19

Q. Define Odd parity

Answer 19

Odd parity means there is always an odd number of 1’s in a word.

Question 20

Data may travel in one way or in two directions what is this called?

Answer 20

Signal can only travel in 1 Direction = Simplex, 2 ways = Duplex

Question 21

What are the first 3 bits of a MIL-STD-1553 word.

Answer 21

Sync

Question 22

Bit encoding for the MIL-STD-1553 is based on what format?

Answer 22

Bi-Phase Manchester 2

Question 23

Define half duplex

Answer 23

When data transmits and receives over the one line but has to wait for its turn for each direction.

Question 24

What is the transmission technique of the MIL-STD-1553?

Answer 24

Half-Duplex

Question 25

Maximum number of terminals on a MIL-STD-1553?

Answer 25

31

Question 26

Transmission media for the MIL-STD-1553?

Answer 26

Twisted shielded pair.

Question 27

MIL-STD-1773 contains information for?

Answer 27

Fibre optic cabling.

Question 28

What does ARINC stand for?

Answer 28

Aeronautical radio inc.

Question 29

ARINC 429 bit encoding?

Answer 29

Bipolar return to zero (RTZ)

Question 30

ARINC 429 Word size?

Answer 30

32 bits

Question 31

What are the characteristics of the ARINC 429?

Answer 31

1. Data bus using two signal wires
2. Word size of 32 bits
3. Bit encoding with bipolar return to zero.
4. Simplex data bus.

Question 32

What system does this schematic belong to?

Answer 32

MILD-STD-1553

Question 33

What system does this schematic belong to? and what does the arrow indicate?

Answer 33

ARINC 429, Arrow indicates simplex

Question 34

Which graph does this represent?

Answer 34

Return to Zero, No signal is transmitted at the Zero

Question 35

What is included in a ARINC 429 Word?

Answer 35

Label, SDI, DATA, SSM, Parity

Question 36

What does the SSM portion of a ARINC 429 word determine?

Answer 36

Validity of the data and a failure warning.

Question 37

What are the first 8 bits of the ARINC 429 word?

Answer 37

LABEL

Question 38

Label codes of a word are typically represented as?

Answer 38

Octal Numbers

Question 39

What is within the LRU of the ARINC 629

Answer 39

Terminal Controller and Serial Interface Module (SIM)

Question 40

The stub cable is coupled to the global data bus via what on the ARINC 629

Answer 40

Current mode coupler

Question 41

The ARINC 629 data bus system includes what parts?

Answer 41

Data bus cable, Current mode couplers, Stub cables.

Question 42

Stub cables are used for?

Answer 42

Bi-directional data movement between LRU and current mode coupler.

Question 43

The bus cable on a ARINC 629 is?

Answer 43

A pair of twisted wires with a termination resistor at each end.

Question 44

What is the message structure of the ARINC 629 system?

Answer 44

Message has upto 31 word strings, 4 bit time gap.

Question 45

Explain the word string of the ARINC 629 system.

Answer 45

Begins with a LABEL and has up to 256 data words.

Question 46

The ARINC 629 uses a time procedure to prevent accidental mixture, what are the 3 timers?

Answer 46

Transmit interval, Synchronization Gap, Terminal Gap.

Question 47

Q. The 3 timers of the ARINC 629 system operate in what 2 ways?

Answer 47

Periodic (Standard Mode) or Aperiodic (Abnormal Events Mode)

Question 48

Which data bus system uses current coupling as the transmission mode?

Answer 48

ARINC 629

Question 49

Number of terminals on the ARINC 629 system

Answer 49

120

Question 50

What is the order from slowest to fastest of the Data bus systems?

Answer 50

1553 1MBps = Slowest
429 = Middle
629 = 2Mbps = Fastest

Question 51

What is the bus architecture of the ARINC 429?

Answer 51

Simplex point to point.