Campbell CR3000 Micrologger, Руководство оператора

Страница: 307 / 644

Section 7. Installation
307
Term: cr
Carriage return
Term: data bits
Number of bits used to describe the data, and fit between the start and stop
bits. Sensors typically use 7 or 8 data bits.
Term: duplex
A serial communication protocol. Serial communications can be simplex,
half-duplex, or full-duplex.
Reading list: simplex
(p. 555),
duplex
(p. 307),
half duplex
(p. 541),
and full duplex
(p.
540).
Term: lf
Line feed. Often associated with carriage return (<cr>). <cr><lf>.
Term: little endian
"Little end first." Placing the most significant integer at the end of a numeric
word, reading left to right. The processor in the CR3000 is MSB, or puts the
most significant integer first. See Endianness
(p. 601).
Term: LSB
Least significant bit (the trailing bit). See the Endianness
(p. 601).
Term: marks and spaces
RS-232 signal levels are inverted logic compared to TTL. The different levels
are called marks and spaces. When referenced to signal ground, the valid RS-
232 voltage level for a mark is –3 to –25, and for a space is +3 to +25 with –3
to + 3 defined as the transition range that contains no information. A mark is
a logic 1 and negative voltage. A space is a logic 0 and positive voltage.
Term: MSB
Most significant bit (the leading bit). See Endianness
(p. 601).