Automating Manufacturing Systems - Process Control and ...

plc glossary - 35.3
background suppression - the ability of a sensing system to discriminate between the signal of interest, and
background noise or signals.
backplane - a circuit board located at the back of a circuit board cabinet. The backplane has connectors that
boards are plugged into as they are added.
backup - a redundant system to replace a system that has failed.
backward chaining - an expert system looks at the results and looks at the rules to see logically how to get
there.
band pressure Level - when measuring the spectrum of a sound, it is generally done by looking at
frequencies in a certain bandwidth. This bandwidth will have a certain pressure value that is an
aggregate for whatever frequencies are in the bandwidth.
base - 1. a substance that will have an excess of HO ions in solution form. This will react with an acid. 2. the
base numbering system used. For example base 10 is decimal, base 2 is binary
baseband - a network strategy in which there is a single carrier frequency, that all connected machines must
watch continually, and participate in each transaction.
BASIC (Beginner’s All-purpose Symbolic Instruction Code) - a computer language designed to allow easy
use of the computer.
batch processing - an outdated method involving running only one program on a computer at once,
sequentially. The only practical use is for very intensive jobs on a supercomputer.
battery backup - a battery based power supply that keeps a computer (or only memory) on when the master
power is off.
BAUD - The maximum number of bits that may be transmitted through a serial line in one second. This also
includes some overhead bits.
baudot code - an old code similar to ASCII for teleprinter machines.
BCC (Block Check Character) - a character that can check the validity of the data in a block.
BCD (Binary Coded Decimal) - numerical digits (0 to 9) are encoded using 4 bits. This allows two
numerical digits to each byte.
beam - a wave of energy waves such as light or sound. A beam implies that it is not radiating in all
directions, and covers an arc or cone of a few degrees.
bearing - a mechanical support between two moving surfaces. Common types are ball bearings (light
weight) and roller bearings (heavy weight), journal bearings (rotating shafts).
beats - if two different sound frequencies are mixed, they will generate other frequencies. if a 1000Hz and
1001Hz sound are heard, a 1Hz (=1000-1001) sound will be perceived.
benchmark - a figure to compare with. If talking about computers, these are often some numbers that can be
use to do relative rankings of speeds, etc. If talking about design, we can benchmark our products
against our competitors to determine our weaknesses.
Bernoulli’s principle - a higher fluid flow rate will result in a lower pressure.
beta ratio - a ratio of pipe diameter to orifice diameter.
beta rays - electrons are emitted from a fission or fusion reaction.
beta site - a software tester who is actually using the software for practical applications, while looking for
bugs. After this stage, software will be released commercially.
big-endian - a strategy for storing or transmitting the most significant byte first.
BIOS (Basic Input Output System) - a set of basic system calls for accessing hardware, or software services
in a computer. This is typically a level lower than the operating system.
binary - a base 2 numbering system with the digits 0 and 1.
bit - a single binary digit. Typically the symbols 0 and 1 are used to represent the bit value.
bit/nibble/byte/word - binary numbers use a 2 value number system (as opposed to the decimal 0-9, binary
uses 0-1). A bit refers to a single binary digit, and as we add digits we get larger numbers. A bit is
1 digit, a nibble is 4 digits, a byte is 8 digits, and a word is 16 digits.