ROTRONIC HygroLog HL-NT - Manual (Page 14)

IN-E-HL-NT-V2_12
Rotronic AG
Bassersdorf, Switzerland
Document code Unit
HygroLog HL-NT data logger:
instruction manual Instruction Manual
Document Type
Page 14 of 48
Document title
© 2009-2012; Rotronic AG IN-E-HL-NT-V2_12
Note: the sensor diagnostics and drift compensation function of the HygroClip 2 probe is not
available with the HygroLog HL-NT due to the fact that the probe is powered only briefly during
each log or measurement interval.
2.10 Event tracking
The HygroLog HL-NT maintains an internal event file with the extension EVT. This function is
always enabled.
Part of the procedure to ensure conformity to the FDA requirements is to use the HW4 software
to disable the MENU key on the HygroLog HL-NT keypad. The MENU key is the only key that can
be used to make changes to the HygroLog HL-NT. When this procedure is implemented, the
events recorded by the HygroLog HL-NT are the result of an interaction with the HW4 software.
When the MENU key is not disabled, a limited number of events are recorded in the logger event
file. In this case no entries are made in the logger event file header. The two tables below provide
a list of the events tracked by the HygroLog HL-NT.
The logger event file is split between the internal memory of the logger (up to 170 events) and the
flash memory card (practically unlimited number of events). HW4 offers the possibility of
downloading, opening and printing the entire file contents. All past logger events are available to
HW4 as long as the flash memory card is not removed from the logger. The serial number of the
logger is used as the file name.
Example: 1111111111.EVT
The logger event file consists of a file header and a file body. The file header provides the
following information:
o Most recent programming of the log function: programming date and time, user and HW4
product ID
o Most recent device configuration: date and time, user and HW4 product ID
o Most recent adjustment to the PC date and time: date and time, user and HW4 product ID
An individual record with date and time is entered in the event file body for each individual event
listed in the two tables below:
Interaction with the HW4 software:
Event Description
Power up
The battery was inserted or the instrument powered down and up after
an internal problem
Watchdog overflow Internal instrument error (normally should not occur)
Writing device
configuration
New or existing configuration written to logger
Memory card removed
While recording data, the logger could not find the memory card. The
data was written to the EEPROM and are not yet lost
Memory card full No free memory space on the memory card