Dialog Box=>Data FilterΒΆ

To import a subgroup of data, a record filter can be specified. For example, a filter to which only data will be imported if a certain channel is above a specified threshold (e.g. Torque > 10 Nm).

../../_images/DataImportFilter_N-en.png

Channel

List of all available numeric and text channels. Channel names may contain the following special characters: ., -, +, $, #, ~, !, ^, &, %. The special characters will be replaces by an underscore.

Comparison Operators

The following operators are available:

Value Meaning
== equal or with tolerance
> greater than
< less than
<= less than or equal
>= greater or equal to
!= not equal to

Value

Type in a value or pick one from the list. The list shows a maximum of 100 elements.

In a filter, numeric and text channels can be used. For text channels the wildcards "*" and "?" can be used. The asterisk character (*) substitutes for zero or more characters. The question mark (?) substitutes for exactly one character. Example Mode == "On*" or Mode != "Off*". Quotes (”) are not allowed in the search text.

Tolerance

For the == operator, a tolerance in percent or an absolute value can be specified. To avoid a tolerance, set the value to 0 or clear the field.

Up to seven filters can be logically linked using one of the following operators:

Value Meaning
AND logical AND
OR logical OR

The AND operator has a higher precedence than the OR operator. Parentheses cannot be used.

Comment

Up to UniPlot R2013.7, it was not possible to define a record filter for NC files with multiple time groups (dimensions). To work around this problem all channels could be interpolated onto one time resolution before the filter was specified. Now a record filter can be defined for MDF, BLF, or Puma recorder data without the interpolation. The filter can use channels from different time groups. The channels will be interpolated to the time resolution of the first channel. The filter channel is saved in the time group of the first channel in the filter. For all other time groups the filter will be calculated on demand.

The record filter is saved in the NC file as a channel. The channel name of the record filter starts with __nc_filter_ followed by the dimension name, for example __nc_filter_group2. The channel contains the value 0 for records that did not pass the filter and otherwise 1

If the record filter is enabled, only data points will be loaded into a dataset where the filter record has the value 1.

In the NC file, global attributes with information about the record filter will be added to the file:

Attribute Name Description
_nc_record_filter_enabled Is 1 if the filter is enabled or 0 if disabled.
_nc_record_filter_text Is the filter text, for example $speed$ > 600 && $torque$ > 10. All channels used in the filter will be interpolated to the resolution of the first channel. The record filter channel will be saved in the dimension of the first data channel.
_nc_record_filter_channel Name of the filter channel, for example __nc_filter_NumPoints1. The filter channel is used to interpolate the filter channel for other dimensions (time groups).
_nc_record_filter_update Is an update counter.

History

Version Description
R2013.7 Record filter can be specified for NC files with multiple data groups, for example MDF files with different time groups. Up to version R2013.6, record filters could only be specified for NC files where all channels had the same number of data points.
R2013.3 Text channels can be used in a filter.
5.14.5 “Extended from 4 to 7 elements. A tolerance can be specified”.

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