2.2. EXTERNAL BATTERY (OPTION)
Most Multilog2 models have a connector that allows an
External Battery to be connected. These provide the logger
with additional power capacity.
An example is shown in Figure 2.
Various battery capacities are available.
Always use HWM supplied batteries to ensure compatibility
and safety. Ensure the cable supplied with the battery is
suitable for the external power connector fitted to your
logger. (6-pin and 10-pin connector versions are available.
See also section 2.7).
(For situations where the use of an external battery is
required, seek the advice of your HWM representative).
2.3. LOGGER OPERATION
The logger software is designed to minimise battery use and thereby prolong the
expected battery life. However, battery life is also affected by user-programable
settings. The user is advised to set the logger tasks and sample frequencies to the
minimum requirements of the intended use in order to manage battery power
effectively.
Where supplied, the external battery power is used to extend the battery life of the
logger or to allow more frequent communications with the host server.
The logger is normally shipped from the factory in an inactive state (referred to as
‘shipping mode’, or ‘sleep mode’) to preserve the life of the battery.
When activated (see section 3), the logger will initially go into the state of “Waiting” (for a
short time). Then it will go into the state of “Recording” and begin repetitive logging of
measurements from the various sensors fitted to the unit, according to its configuration
and settings.
The logger operates using two time periods, known as the “sample period” and the “log
period”. It will sample the sensors at the sample rate to create temporary measurement
samples; this is a repetitive background task. After taking several measurement
samples, some statistical functions can be optionally applied to produce a datapoint that
is logged (saved) at the log rate; these form the recorded (logged) measurements and
are saved into an area of memory which is referred to as the “primary recording”.
The log period is always a multiple of the sample period.
If the logger has the feature enabled, it can also be set to occasionally save additional
data into a “secondary recording” memory area (see section 2.4), (e.g., data sampled at a
higher frequency, such as by using the “sample period” rather than the “log period”).
Note: This is not available on all supplied units and must be arranged through your
sales representative before placing an order; it has implications concerning
expected battery life of the unit.
The logger will also have daily tasks at set times, such as uploading its unsent data over
the internet. When sending data, the logger waits to receive confirmation from the
