Instructions

UM-0085-B09 DT80 Range User Manual Page 411
RG
 retrieve
To unload or return data and other information from the DT80 to the host computer, either by:
• Unloading through one of the DT80’s communications interfaces
• Unloading by temporarily inserting a USB memory device into the DT80

ROM
Read Only Memory. Memory that can be randomly read from but not normally written to. The DT80 uses flash ROM.
 RS 232
A common communications and interface standard for connecting two serial devices in a point to point configuration.
RS232 uses a negative voltage (typically –5V) to represent a logic "0" and a positive voltage (typically +5V) to
represent a logic "1". These signals are with respect to a common ground terminal, hence RS232 is said to use
single-ended signalling.
 RS-422
Another communications interface standard for point to point connection of serial devices. RS-422 uses differential
signalling (a pair of wires for each signal, no signal-ground connection) which provides improved noise immunity and
allows operation over longer distances than RS-232.
 RS-485
Yet another communications interface standard. Like RS-422, RS-485 uses differential signalling. RS-485 is
designed for multi-drop operation over a single shared pair of wires. RS-485 is therefore a half duplex protocol –
only one device can transmit at any one time.
 RTD
Resistance Temperature Detector. A resistive sensor that changes resistance with changes in temperature.
 sampling speed
The maximum rate at which analog-to-digital conversions can be done. This includes any channel selection time,
settling time (for the signal to stabilise) and processing time (if required).
 SCADA
Supervisory Control and Data Acquisition (SCADA) systems are used to monitor and control plant status and
provide data logging facilities.
 schedule
A collection of channel definitions which will be evaluated when a certain trigger condition is true (e.g. the required
time interval has elapsed, or a digital input has changed state)
 schedule header
The schedule’s ID and trigger, e.g. RA1S — see Figure 7 (P48).
 SDI-12
Serial Data Interface – 1200 baud. A 3-wire multi-drop serial sensor interface, and associated protocol.
 serial
One by one. In serial data transfer, data is sent in a single stream of bits, one bit at a time, one after the other. The
opposite of serial is parallel. In parallel data transfer, several streams of bits are sent concurrently.
 settling time
The time allowed for the input signal to the ADC to stabilise before it is measured. This can be controlled using the
measurement delay (MDn) channel option.

shared-terminal inputs
Analog inputs where a common reference is used. Also called single-ended inputs. For example, the
1*V, 1+V and
1-V commands all measure single-ended voltages relative to a common point (the 1# terminal)
See Shared-Terminal Analog Inputs (P23).
 shield
A conductor surrounding input signal wires that is generally connected to the DT80's ground. The purpose is to
shield the input signal from capacitively-coupled electrical noise. Such a shield provides little protection from
magnetically-induced noise.

SIM
Subscriber Identity Module – a small card which electronically identifies a mobile subscriber. The DT8xM loggers
require a SIM card in order to be able to connect to a mobile network.