UM-0090-B1E
DT90 Range User Manual
Page 31
RG
Glossary
3G/ 4G modem
A device or module that allows a computer to connect to the Internet via a 3G/ 4G network connection.
4
–20 mA
A common industrial measurement standard. A transmitter controls a current in the range of 4 to 20mA as a function
of a measurement parameter. Any receiver(s) or indicator(s) placed in series can output a reading of the parameter.
Main advantage is 2-wire connection and high immunity to noise pick-up.
Ω
Ohm, a unit of resistance
channel
Describes a measurement to take, or a control action to perform.
Firmware
The "operating system" stored inside the DT90. The DT90’s firmware is user-upgradeable.
FTP
File Transfer Protocol. A TCP/IP protocol for copying files from one computer to another.
Modbus
A widely used control and automation communications protocol, often used in SCADA systems.
PLC
Programmable Logic Controller. Used to automate monitoring and control of industrial equipment.
resolution
The smallest detectable increment of measurement
— that is, the smallest change in input that produces a
detectable change in output. In the field of data acquisition, resolution is the number of bits that the ADC uses to
represent the analog signal
— the greater the resolution, the smaller the changes in input signal that can be
resolved/detected.
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)
SIM
Subscriber Identity Module
– a small card which electronically identifies a mobile subscriber. The DT90 loggers
require a SIM card in order to be able to connect to a mobile network.
transducer
A device that converts a physical parameter (temperature, for example) into an electrical voltage or current. It is
usually a sensor with additional electronics for signal conditioning and scaling.
USB
Universal Serial Bus. A standard method of connecting peripheral devices to a host computer. The DT90 operates
USB device for programming via host computer.
