USER'S GUIDE____________________________________________________________________
68 __________________________________________________________________ M210704EN-F
Data Logger Module
The optional data logger module extends the data storage for the
measurement data. When the data logger is present, this storage is
automatically used by the transmitter. The stored data can be browsed
using the optional display module, and accessed through the serial
connections. See sections Graphic History on page 73 and Data
Recording on page 120.
The data logger module contains non-volatile flash memory providing
4 years and 5 months of storage for 4 parameters at a 10-second sampling
interval. When the memory is full, the data recording will not stop.
Instead, the oldest data is overwritten. For each parameter and
observation period, the module stores the minimum and maximum values
during the interval, as well a data trend value that is averaged from
samples taken during the interval (see Table 8 on page 68).
Table 8
Observation Periods and Resolution
Observation Period
Period for Trend/Max/Min
Calculations (Resolution)
3 hours
90 seconds
1 day
12 minutes
10 days
2 hours
2 months
12 hours
1 year
3 days
4 years
12 days
The quantities that are logged are the same that have been selected for
measurement using the display/keypad or the serial line. When taking the
transmitter into use, verify that the desired quantities are selected. If you
change the quantities later, the transmitter will start logging the new
quantities, and stop logging the quantities that are no longer selected.
Changing the quantities does not delete any measurement data that is
already in memory. However, the data of any removed quantity cannot be
accessed unless the quantity is re-activated first.
The data logger module has a real time clock with a battery back-up. The
clock has been set to the Coordinated Universal Time (UTC) at the
factory, and its time cannot be set by the user. The data that is stored in
the logger's memory is timestamped using the logger's clock.
When date and time are set on the transmitter, they are stored to the
transmitter's memory as an offset from the time on the logger's clock.
When browsing the stored data, the time offset is applied to the
timestamps shown in the graphical history, and data outputted from the
serial port. The timestamps in the data logger's memory remain as they
were originally stored.
