C
HAPTER
1 A
CQUISITION
? L
OGGING
?…: Important Terminology
11
UM-0071-A0
Internal Memory-Backup Battery
In addition to the main internal battery, the DT800
contains a small 3.6V lithium
internal memory-backup
battery
that ensures your data, real-time clock and
primary settings are not lost if power to the logger is
interrupted. The backup battery can maintain this
information for up to 12 months if necessary.
Sleep Mode
To conserve battery power, the DT800 “goes to sleep”
if it has no measurements to do and there has been no
communication for a period of 30 seconds.
This applies only if the logger is powered by its internal
battery. If it’s powered from an external source, the
DT800 never goes to sleep (unless you override this
default behaviour).
In sleep mode, most of the internal electronics shuts
down. The current drain drops from 400mA when
awake to a tiny 250µA when asleep; just 0.07% of the
awake value.
Auto-Sleep in the Event of Power
Supply Failure
If the power supply to the DT800 drops below 9.5
volts, the logger automatically attempts to minimize its
power requirements and maintain any logged data
and settings by going to sleep. When the supply is
restored, the logger senses this and automatically
returns to its previous mode of operation.
1-2
I
MPORTANT
T
ERMINOLOGY
This section introduces you to some data acquisition
and logging terms you’ll need right away. Others are
explained as they arise.
Sensors and Transducers
Origins of data in a data acquisition and logging
system.
Sensors
are the raw, basic devices that detect variable
quantities (temperature, pressure, flow,…) and convert
them into electrical signals. Sensors see, hear, taste,
sniff or feel the environment and tell the DT800 (in
electrical terms) what’s going on.
If electronic components are added to a sensor, the
result is sometimes called a
transducer
. The electronics
may be added to excite, amplify, compensate,
linearize, filter or interface to other equipment.
If the electronics include a software-controlled
microprocessor, the result is a
smart sensor
.
Power-up
Applying power to a previously un-powered device.
Format
With
dataTaker, you can “format” data in a variety of
ways. That is, you can arrange the physical
appearance and layout of data as it comes from the
DT800 so that it best suits the way you want to use it.
Host Computer
The computer you use for supervising the DT800.
Host Software
The software you run on the host computer to supervise
the DT800 (
DeLogger
,
DeLogger Pro
and
DeTransfer
,
for example). See the Extras panel “DT800 Host
Software” on page 16.
PC Card
A plug-in card meeting the PCMCIA standard
(Personal Computer Memory Card International
Association). It can be a storage card such as an ATA
Flash card, or a communications device such as a
PSTN modem card or GSM modem card.
Summary of Contents for DT800
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