IDEC SmartRelay functions
IDEC SmartRelay Manual
124
4.3.3
Backup of the real-time clock
Because the internal real-time clock of an IDEC SmartRelay
is backed up, it continues operation after a power failure.
The ambient temperature influences the backup time. At an
ambient temperature of 25°C, the typical backup time is 80
hours.
If there is a power outage of an IDEC SmartRelay for more
than 80 hours, the internal clock responds, as shown below:
On restarting, the clock is set to "Sunday 00:00 1 January". The
time is stopped and flashes. IDEC SmartRelay is back in the
status that it was in before the power outage. In the RUN status,
the system processes the counters that were parameterized
with the time above. The clock is, however, still stopped.
4.3.4
Retentivity
The switching states and counter values of SFs can be set
retentive. This means that current data are retained after a
power failure, and that the block resumes operation at the
break point. The timer is not reset, but resumes operation
until the time-to-go has expired, for example.
To enable this response, however, the relevant functions
must be set retentive. Two options are available:
R: The data is retained.
/
: Current data is not retained (default). See the example on
page 88.
SFs Operating hours counter, Seven-day time switch,
Twelve-month time switch and PI controller are always re-
tentive.
4.3.5
Parameter protection
In the parameter protection settings, you can determine
whether or not the parameters can be displayed and edited
in IDEC SmartRelay parameter assignment mode. Two op-
tions are available:
+
: The parameter attribute permits read/write access in pa-
rameter assignment mode (default).
–
: The parameter settings are read/write protected in param-
eter assignment mode, and can be edited only in program-
ming mode. See the example on page 88.
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