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10 Measured value memory/data logger
VEGAMET 862 • 4 … 20 mA/HART
58867-EN-200312
10 Measured value memory/data logger
With the measured value memory, the measured values of a VEGA
instrument can be recorded and monitored. There are two different
possibilities of measured value recording:
The data are saved over a certain period in the instrument and can
be read out again later on. Via PACTware and DTM different record
-
ing conditions can be set and the process can be started or stopped.
The max. recording period is limited by the memory of the controller.
The max. recording period differs depending on the recording type
(interval or measured value difference).
When recording with interval, a total of 174,000 measured values can
be recorded, when recording with measured value difference, the
value is reduced to 131,000. If measured values are stored in intervals
of e.g. one minute, this results in a duration of 120 days. If more than
one curve is recorded, this time is reduced accordingly.
Note:
The recorded data are written in a period of two to five minutes from
the internal RAM to a flash disk. In case of voltage failure, recordings
of the last minutes can get lost.
The data are only saved on the PC during an online connection with
PACTware and DTM. The max. recording period is limited only by the
storage space on the hard disc.
10.1 Setting the measured value memory
The settings are carried out in the DTM under the menu item "
Di-
agnostics - Measured value memory - Settings
". Up to 3 curves are
available. If required, these curves are activated or deactivated/delet-
ed on this side. By pushing the button "
Add
", an installation assistant
for creating the selected curve is started. The following settings are
carried out step-by-step:
In the first step you have to select the requested measurement loop
and the measured value.
Here you set the requested recording interval. The following options
are possible:
•
"
In time interval
": Recording is carried out in certain adjustable
time intervals
•
"
With measured value difference
": Recording is carried out meas-
ured value dependent with adjustable measured value difference
A combination of the two recording modes is also possible.
To enable a specific monitoring, the start and stop conditions can be
set for the recording in dependence on the current measured value.
If a start condition is met, the recording starts in the instrument. The
current recording stops as soon as the stop condition is reached. If
the start condition is fulfilled again, the recording does not switch on
again.
Measured value memory
Measured value memory
(DTM)
Measurement loop/Meas-
ured value
Recording mode
Start/Stop conditions
