Analog Signals and 4–20 mA Industrial Communications Quiz

The circuit that provided this mode of operation was originally called ______

Unidirectional” is a more appropriate name for this mode of transmission and using the name for this circuit would be much more ______

Half-duplex communication functions much like meaningful human conversation does, that is, one speaker at a time and one ______

In duplex mode, communication can travel in both directions simultaneously: from A to B and from B to A at the same ______

A digital signal is defined as one with defined discrete states; no other state can ______

Binary digital signals have only two states: a binary digit is either a “______” or a “0.”

One of the bit patterns to be organized has to represent ______, for in order for data organization to yield anything usable to humans, it is necessary to store and present information in a human-readable form

American Standard Code for Information Interchange is an example of a ______ coding

A standard signal is one that has the approval of the users and/or a standardization agency; it specifies a way to organize ______

An analog signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e. ______

In data communications, there are three modes of transmission: ______, half-duplex, and duplex

A portion of this chapter —the discussion of data organization sometimes called a ______ —is almost a technical history in itself

Data communications topologies are organized as ______, one-to-many, or many-to-many

In any communication there must be a source and one or more ______

The purpose of communication is to transmit data from the source to the ______

The differences between a “mode” and a “circuit” are rather ______

The purpose of communication is to transmit data from the ______ to the destination

In this mode, communication occurs only in one direction —never in the opposite direction; in figure 1-2 it is from Station A to Station ______

In data communications, the media we use are: electrical conductors , light pipes , and ______ transmission

A communications channel may consist of a communications circuit, which can be either a hardware configuration or a “______” circuit

An 84th character, called the block parity character, was added to the end of the transmitted block to determine if parity was met for all the characters in the block, parity was determined ______ for the Parity row by counting the 1s in the 83 counted columns

Error Correction In addition to having bits devoted to assisting with error detection, what means could be used to correct an error, once one was detected. The answer is normally an automatic retransmission query , known as an ______

Cyclic Redundancy Checks Any time data is placed on a medium , magnetic or optical rotating media, and fiber cable), there is a probability of error; thus, an error detection scheme must be used Most modern devices use a far more efficient scheme of error detection than parity checking Though ASCII was designed for a vertical and horizontal blockchecking code, it can also be used with a ______ scheme that creates a check character

Checksum Any of a number of error-detection codes may be called a ______; however, they are actually cyclic codes, whereas a checksum was originally designed as a linear code

ARQ What hasn’t yet been explained is what happens when an error is detected The following is a simplified discussion of a generalized automatic retransmission query , the ARQ method of error correction Before beginning our discussion, it is important to note the change in terminology as multiple terms are used to refer to the data being transmitted Prior to HDLC, data sent was defined by control characters and was referred to as data ______

Since 1990, the terminology has been changed again ; the Layer 2 octets are called frames and the arrangement of data in Layers 3 and above is referred to as packet data ______

Forward Error Correction Although the ARQ method of error correction discussed above detects an error and then retransmits the portion of the message that was in error, what happens when there is ______ transmission

The efficiency of a checksum in detecting errors is not as high as with a cyclic code, yet the circuitry to produce the checksum is less ______

Some of these codes are cyclic, some are linear, some are quasi-cyclic, and some are ______

THE FRAME IS RECEIVED Forward Error Correction Although the ARQ method of error correction discussed above detects an error and then retransmits the portion of the message that was in error, what happens when there is ______ transmission

The ARQ method will not receive an ______ because the circuit is unidirectional

ASYNCHRONOUS generally means that something may occur at any time and its occurrence is not tied to any other ______

BAUD RATE is the line modulation rate; that is, the number of signal changes per second that are placed on the communication medium in a given ______

Character-Based Protocol: The IBM Bi-Sync protocol, one of the first and most widely used of the proprietary protocols, was developed to link the IBM 3270 line of terminals to IBM computers in a ______ manner

Bit-oriented protocols use a concept called ______, where there are bit patterns before and after the information frame

WE HAVE LOOKED AT TWO PROTOCOLS, ONE CHARACTER-BASED AND ONE BIT-ORIENTED THE BIT-ORIENTED PROTOCOLS DO NOT DEPEND ON THE DATA STREAM CONTENTS; THEY OPERATE INDEPENDENTLY ______ THE DATA

BitOriented Protocol: FIGURE 1-12 ILLUSTRATES 0 INSERTION AND ______

In this chapter we have reviewed the organization of data, as organized into characters and as organized to detect errors in ______

The first data transmission code devoted more overhead to the error-detection scheme than to the data ______

More than anything, this chapter has served to introduce you to the foundational concepts of data communications and how communications are organized into modes of transmission, into character codes, and into ______

In duplex mode, communication can travel in both directions simultaneously: from A to B and from B to A at the same ______

Half-duplex communication functions much like meaningful human conversation does, that is, one speaker at a time and one ______

An analog signal is a model representing quantities at any value between a specified set of upper and lower limits. The 4–20 mA signal is one of the most commonly used industrial communications standards and it is used in the two-wire current loop that connects devices in an instrument circuit. The reader needs to become familiar with the terms: voltage, current, resistance, impedance, capacitive reactance, and inductive reactance. ______ is the difference in electrical potential that is necessary prior to any work being performed.

An analog signal is a model representing quantities at any value between a specified set of upper and lower limits. The 4–20 mA signal is one of the most commonly used industrial communications standards and it is used in the two-wire current loop that connects devices in an instrument circuit. The reader needs to become familiar with the terms: voltage, current, resistance, impedance, capacitive reactance, and inductive reactance. Voltage is the difference in electrical potential that is necessary prior to any work being performed.

An analog signal is a model representing quantities at any value between a specified set of upper and lower limits. The 4–20 mA signal is one of the most commonly used industrial communications standards and it is used in the two-wire current loop that connects devices in an instrument circuit. The reader needs to become familiar with the terms: voltage, current, resistance, impedance, capacitive reactance, and inductive reactance. Voltage is the difference in electrical potential that is necessary prior to any work being performed.

An analog signal is a model representing quantities at any value between a specified set of upper and lower limits. The 4–20 mA signal is one of the most commonly used industrial communications standards and it is used in the two-wire current loop that connects devices in an instrument circuit. The reader needs to become familiar with the terms: voltage, current, resistance, impedance, capacitive reactance, and inductive reactance. Voltage is the difference in electrical potential that is necessary prior to any work being performed.