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 (typ5V) 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
.
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.
Содержание DT80
Страница 29: ...UM 0085 B09 DT80 Range User Manual Page 29 RG The DT80 File System P114 ...
Страница 184: ...UM 0085 B09 DT80 Range User Manual Page 184 RG Figure 71 DT80 communications options ...
Страница 185: ...UM 0085 B09 DT80 Range User Manual Page 185 RG Figure 72 DT80 communications options integrated modem models ...