Rievtech EXM-12DC-DA-R-HMI, User Manual

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When 0.02 % of the time T is smaller than 0.02 seconds, the maximum deviation is 0.02 seconds.
Example: The maximum tolerance per hour (3600 seconds) is ±0.02%, which is proportional to ± 0.72
seconds. The maximum tolerance per minute (60 seconds) is ± 0.02 seconds.
Accuracy of the timer (weekly/yearly timer)
The maximum timing in accuracy is ± 5 s/day.
6.4.3 Backup of the real-time clock
Because the internal real-time clock of an x-Messenger 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 of x-Messenger is 100 hours.
6.4.4 Retentivity
The switching states and counter values of SFs can be set retentive. This means that current data is 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.
R: The data is retained.
/: Current data is not retained (default). See the section in topic "Second circuit program
" on enabling and disabling retentivity.
SFs hours counter, weekly timer, yearly timer and PI controller are always retentive.
6.4.5 Parameter protection
In the parameter protection settings, you can determine whether or not the parameters can be displayed and
edited in x-Messenger parameter assignment mode. Two options are available:
+: The parameter attribute permits read/write access in parameter assignment mode(default).
-: The parameter settings are read–/write–protected in parameter assignment mode, and can be edited
only in programming mode. See the parameter protection mode example in the "Second circuit program".
6.4.6 Calculating the gain and offset of analog values
A sensor is connected to the analog input and converts a process variable into an electrical signal. This value
of signal lies within the typical range of this sensor. x-Messenger always converts the electrical signals at the