Midterm Review Flashcards
Advantages of using fiber optics vs copper cabling
Increased bandwidth
noise immunity
lower power consumption
Undesirable electrical signals which distort or interfere with the original signal
Noise
Maximum cable length for RS-485 utilizing a copper conductor
1200 meters
How many drivers/masters are allowed on an RS-232 segment?
1
How many receiver/slaves are allowed on an RS-422 segment?
10
statements about RS-232
RxD carries data from the DCE to corresponding pin on the DTE
CTS is an output from the DCE
DCE stands for Data Communication Equipment
The maximum Baud rate for RS-485 is
10 Mbps
Cable used to connect a DCE device to a DTE device
Straight through cable
_____is NOT considered a common data code used in modern data communication systems?
Morse
DCS Manufacturer and system name, was the first on the market
Yokogawa, Centum
In what year was the first DCS system commissioned?
1975
The rate at which a signal changes
Baud Rate
The four most important control devices
DCS, PLC, Smart Instruments and microprocessors
A system that has been superseded by newer technology
legacy control system
DCS
Distributed Control System
How many bits are in a byte
8
4 bits
nibble
4 bytes
IP
2 nibbles
1 byte
max integer
255
Communication mode used for simultaneous bidirectional communications
Full duplex
Basic Cable types
Fiber Optic cable
Coaxial cable
twisted pair cable
two wire
The speed of an RS-232 transmission is inversely proportional to the length of the cable
true
An asynchronous system incorporates a clock signal so the receiver and transmitter can remain synchronized
false (it has no global clock)
a modem is used to convert digital data to an analog signal for transmission over long distances
true
A two wire RS422 system is capable of communicating in a full duplex manner
False (4 wires)
A two wire RS232 system is capable of communicating in a full duplex manner
True
A four wire RS485 system is capable of communicating in a full duplex manner
True
A balance, 4 wire transmission system, is only capable of half duplex communications
false (capable of full)t
Emile Baudot was the inventor of the first practical telegraph system
false ( he came up with the baud code, baud rate was named after him)
Samuel Morse used 5 bits to represent his 32 characters for serial data transmission
False
the general property of any copper cable type if that attenuation increases as frequency decreases
False
A frequency of 2200 Hz represents a 1 in HART protocol
False
10 micron single mode fiber optic cable has the ability to transfer data up to 10000 metres in distance
true
A modem is used to convert analog data to a digital signal for transmission over long distances
false
The resistance of a copper cable increases as the cross sectional area increases
false
A #20AWG cable has a larger diameter than a #14AWG cable
false
electrical noise coupling methods
electromagnetic radiation electrostatic Impedance magnetic is this right?
The RS-485 system utilizes a balanced transmission system which requires 2 conductors per signal
true
The RS serial communication standard use a POSITIVE voltage to define a logic 0 state, and a NEGATIVE voltage to represent a logic 1 state for DATA lines
true
The RS serial communication standard use a NEGATIVE voltage to define a logic 0 state, and a POSITIVE voltage to represent a logic 1 state for CONTROL lines
true
resistors at the end of the serial bus topologies are
100-120 ohms
