X20 system modules • Other functions • X20CM4810
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X20 system User's Manual 3.10
4.26.2.5.8 Module registers - Minimum and maximum values
The characteristic values of the X20CM4810 are recalculated every 300 ms. To prevent values from being lost, it is
necessary to collect this data quickly enough. If this is not possible, the characteristic values on the module can be
locked using the RequestDataLock01 data point and then read asynchronously in Function model 2 - Slow master
and Function model 254 - Bus controller. However, this method results in measurements being lost.
To prevent measurements from being lost, a special function has been implemented in the X20CM4810 that records
the minimum and maximum values of all characteristic values calculated in the module. When an edge of the
MinMaxUpdate01 data point occurs, a new measurement can be started whereby the minimum and maximum
values are reinitialized. The current data is copied to the asynchronous register at the same time.
The number of collected measurements can then be read using the asynchronous data point "MinMaxCounter01".
The respective values are read using the asynchronous minimum and maximum data points.
Example
For
Iso10816
, these are the
Iso10816Min01-04
and
Iso10816Max01-04 registers
.
Information:
•
If data is locked with RequestDataLock01, no further measurement values are collected. This
only affects Function model 2 - Slow master and Function model 254 - Bus controller since the
characteristic values are not locked in the standard function model.
•
If a characteristic value overflow or open line occurs, no new values are collected.
•
The minimum and maximum data points are each initialized using the maximum and minimum
of the respective data type (see 4.26.2.2.11 "Characteristic value format" on page 2075). If there
is no valid value on the characteristic value for the overall measurement, then the initial value
is retained (e.g. on overflow, open line or locked data).
•
If the data on the module is locked (DataLockValid01 = 1), then no new values are added when
determining the minimum. The measurement cycles are still counted, however.
Registers are only updated at an edge from "MinMaxUpdate01" and are only valid if "MinMaxCounter01" is not
equal to 0. The asynchronous register "MinMaxCounter01" specifies the collected measurement cycles for the
minimum and maximum.
4.26.2.5.8.1 CrestFactorRawMax01-04
Asynchronous maximum value of the "CrestFactorRaw" characteristic value of the respective channel in thou-
sandths.
Since division by the RMS value takes place in the module ("RmsRaw"), there may be an overflow if the RMS value
is very small. To prevent this, the module has an internal lower limit of 1 mg for the RMS value.
See also section 4.26.2.5.8 "Module registers - Minimum and maximum values" on page 2178 for additional in-
formation.
4.26.2.5.8.2 CrestFactorRawMin01-04
Asynchronous minimum value of the "CrestFactorRaw" characteristic value of the respective channel in thou-
sandths.
Since division by the RMS value takes place in the module ("RmsRaw"), there may be an overflow if the RMS value
is very small. To prevent this, the module has an internal lower limit of 1 mg for the RMS value.
See also section 4.26.2.5.8 "Module registers - Minimum and maximum values" on page 2178 for additional in-
formation.
4.26.2.5.8.3 FrequencyBandMax01-32
Asynchronous maximum value of the respective frequency band in thousandths of a mm/s or g depending on the
configuration. See also section 4.26.2.5.8 "Module registers - Minimum and maximum values" on page 2178 and
4.26.2.2.9 "Frequency bands" on page 2074 for additional information.
If the frequency band parameter is set to a velocity signal, then this value is only calculated if the EnableVelocity-
Calculation bit (configured in the "SensorConfig01" register) for the respective channel is set; otherwise, 0 is output.
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