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12. The logging function
The logging function is always on.
The instrument can store 9000 samples. The memory is
arranged in circular mode: once full, the most recent data will overwrite the oldest ones. There
is no memory clearing command.
Each sample stores date and time, temperature, relative humidity, absolute humidity, mixing
ratio, dew point, and wet bulb temperature value of the three analog outputs and state of the
three relays (if present).
When modifying the logging interval the current logging session is ended and a new one is
started.
The sessions are numbered from 0 to 255, the number is incremented until 255, then it
restarts from 0. The progressive index is used to mark the different sessions.
The following brings about a session change:
Modifying the log interval
Modifying the date and time
Suspend mode
Off-line mode
Power failure
After a power failure, the instrument can restart logging, from the session after the power
failure,
provided that the internal clock battery is not discharged
. If the clock battery is
discharged, the instrument will start from the initial page zero, overwriting the existing data.
In this case, this date is wrong.
The available logging interval are: 1, 2, 5, 10, 20, 60, 120, 240 seconds.
Each stored data represents the AVERAGE of the measurements performed every
second during the logging interval
. For example, by selecting a 20 second logging interval,
each stored data is the average over 20 seconds. Therefore, the instrument does not log the
immediate quantity measured at the end of the interval, but the average on the entire interval.
The instrument performs a measurement every second
. In the example, you will get an
average over 20 samples.
The state of each relay is stored as follows: “0” if, during the logging interval, the relay is
always de-energised, “1” if it is always energised, “V” for both conditions.
The memory capacity goes from a minimum of 2 hours and 30 minutes to a maximum of 25
days, as reported in the table below.
Logging interval (sec)
Storage capacity
1
2 hours and 30 minutes
2
5 hours
5
12 hours and 30 minutes
10
1 day and 1 hour
20
2 days and 6 hours
60
4 days and 4 hours
120
8 days and 8 hours
240
25 days
The sessions in the memory can be downloaded to a PC using the DeltaLog12 software: during
download, the system continues to log the new measurements, without interruption.
To protect the logged data and avoid overwriting, you can stop logging using the DeltaLog12
software. After the download, you can restart logging using the DeltaLog12 software.
Summary of Contents for HD2817T Series
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