DataHog2+
1.0 Introduction
The SDL 5000 series of DataHog2+ dataloggers comprise an electronically advanced
datalogging system for a variety of environmental sensors.
The logger is centred on a high performance generation 8 bit microprocessor (p). This
has the ability to perform all the mathematical and logging tasks and then close down to
conserve power.
Depending on the datalogger model there are one or more analogue to digital
converters which render the signals from the sensor into a digital form that can be
handled by the microprocessor. These have a resolution of 15 bits which means that
analogue signals such as light, which vary over several decades, can be properly
handled and give adequate resolution of measurement over the required range.
Many versions of the DataHog2+ are available, with different combinations of voltage,
current and digital inputs. This manual covers all models, and so will include sections that
are not applicable to individual units. Please check those parts of the manual that apply
to your model and type of your unit and ignore inapplicable sections.
In normal logging mode the p will be ‘woken up’ by the clock at regular 10 second
intervals. The p will keep track of real time by counting the number of times it is woken
up and storing the time in the RAM while the p is asleep! nce woken up, the
microprocessor will perform the tasks required of it (depending on the logging mode
previously selected) and then when these are complete will return to ‘sleep’ to conserve
power.
The microprocessor can communicate with the user’s host computer via its built in RS232
interface, and can be controlled by instructions sent via this. It also gives some feedback
to the user via the audio transducer (beeper) built in.
Immediately before the p closes down to ‘sleep’ mode, if there is a plug connected to
the 8 pin RS 232 socket, then it will ‘listen’ for a command from the user for a period of
about 1 second. During this time, preceded by an audible ‘beep’, any numeric character
sent to the DataHog2+ will cause it to enter terminal (or Main Menu) mode.
The datalogger is usually contained in a polycarbonate housing, which is sealed to IP
65. The sockets, when mated to a matching plug or blanking unit are also weatherproof
to IP65.
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