Kipp & Zonen LOGBOX SD, Instruction Manual, Page: 12 / 53

12
seconds when input was in logical high level over one minute. The same applies to
all logging intervals over one minute.
With logging intervals of 10s, 20s and 30s only counter and time options are
available.
When long time data recording is required, it is possible to use the SD memory card.
LOGBOX SD can accept any memory size above 128MB. After inserting the card in the
data logger, processor checks size of the card and proper formatting. If necessary,
LOGBOX SD will format the card (its own format) and starts to write data to SD
memory card. If the user wants to remove the card, it is recommended to put the
data logger to sleep mode first and wait until indication LED turns off. Then the file
is correctly closed and the card can be removed. It is possible to read it directly in
your card reader in the PC. In the case the user will remove the card during run mode
(but LED must be off), files on the card will remain, but the last file will be not
correctly closed but still readable on the PC.
The whole design is oriented to ultra low power consumption. This approach was
driving during design of power management circuitry. The measurements on analog
inputs take a few seconds (depending on configuration). During the logging interval
(which can be selected from 10 seconds to 60 minutes) it is necessary to switch the
instrument to sleep mode when measurements are not active. This way it maximizes
battery life. Power consumption during measurement is less than 5mA, in the sleep
mode it is about 20uA (without SD card). This periodical switching is performed by
the power management circuitry itself and user does not need to care for it.
Measuring on digital inputs is active during all the time.
As many sensors have a start up-time after power on, it is necessary to make
measurements after their outputs are fully settled. The delay has to be adjusted to
the slowest sensor. This feature is included in LOGBOX SD. The delay parameter sets
the time after power up from sleep mode to actual measurements. It can be in the
range from 0 to 9 seconds. There is a built in solid state relay and battery switch for
switching power to the sensors. No other switching devices are necessary.
For the real time circuit there is a separate clock battery. It is a lithium battery with
3V nominal voltage, type CR2032. Exchange is simple for the user. After exchange of
the battery, it is necessary to readjust time and date.
LOGBOX SD is working in three basic modes: measuring, sleep and transport. During
measuring period all components are active; all measurements based on actual
configuration are performed, measured values are converted to engineering units.
Then record of output values is stored in the memory and SD card and data are sent
to the serial line (both RS232 and RS485). Finally, LOGBOX SD goes to sleep mode.
In sleep mode there is activity only in real time circuit, digital inputs measurements
and serial line (RS232) input. This situation lasts for the whole logging period.
During sleep mode it is also possible to switch to service mode (to setup
configuration). After pressing CTRL+BREAK once (on PC in terminal mode) it is
activated. Escape back to sleep mode is done with the Q command.
Transport mode is equivalent to switch off. It is intended for use
during transport or long time storage. During this period only real
time (clock) circuitry runs and all other parts are not functional.
In
transport mode it is necessary to remove SD card for power
saving.