Campbell Scientific CR1000 Measurement and Control System - Manual (Page 464)

Section 11. Glossary
464
RMS
Root‐mean square, or quadratic mean. A measure of the magnitude of
wave or other varying quantities around zero.
RS‐232
Recommended Standard 232. A loose standard defining how two
computing devices can communicate with each other. The
implementation of RS‐232 in Campbell Scientific dataloggers to PC
communications is quite rigid, but transparent to most users.
Implementation of RS‐232 in Campbell Scientific datalogger to RS‐232
smart‐sensor communications is quite flexible.
sample rate
The rate at which measurements are made. The measurement sample
rate is primarily of interest when considering the effect of time skew
(i.e., how close in time are a series of measurements). The maximum
sample rates are the rates at which measurements are made when
initiated by a single instruction with multiple repetitions.
scan interval
The time interval between initiating each execution of a given Scan() of
a CRBasic program. If the Scan()
Interval is evenly divisible into 24 hours
(86,400 seconds), it is synchronized with the 24‐hour clock, so that the
program is executed at midnight and every Scan()
Interval thereafter.
The program is executed for the first time at the first occurrence of the
Scan()
Interval after compilation. If the Scan() Interval does not divide
evenly into 24 hours, execution will start on the first even second after
compilation.
scan time
When time functions are run inside the Scan() / NextScan construct,
time stamps are based on when the scan was started according to the
CR1000 clock. Resolution of scan time is equal to the length of the scan.
See system time
(p. 468).
SDI‐12
Serial Data Interface at 1200 bps. Communication protocol for
transferring data between data recorders and sensors.
SDM
Synchronous device for measurement. A processor‐based peripheral
device or sensor that communicates with the CR1000 via hardwire over
a short distance using a proprietary protocol.