Rockwell Automation 1440-VDRP06-00RH XM-160/161/162 Direct Vibration Module - Manual (Page 71)

Publication GMSI10-UM025C-EN-P - August 2010
Configuration Parameters 63
Channel Overall
Measurement Parameter There are six instances of the overall measurement parameter, one for each
channel. Use this parameter to configure the filtering performed for each
overall measurement.
High Pass Filter Sets the high pass filter to apply to the
measurements. The high pass filter is useful in
removing low frequency signal components that
would dominate the signal. The high pass filter
attenuates all frequencies below a defined
frequency. It allows, or passes, frequencies above
the defined frequency. Options: 3Hz
10Hz
Low Pass Filter Sets the frequency above which the input signal will
be significantly attenuated. Options: 1000Hz
5000Hz
Very Low HPF Frequency (EDS
File only) Shows the corner frequency for the Very Low high
pass filter option.
Low HPF Frequency (EDS File
only) Shows the corner frequency for the Low high pass
filter option.
Low LPF Frequency (EDS File
only) Shows the corner frequency for the Low low pass
filter option.
High LPF Frequency (EDS File
only) Shows the corner frequency for the High low pass
filter option.
Channel Signal Processing Parameters
Parameter Name Description Values/Comments
Overall Measurement Parameter
Parameter Name Description Values/Comments
Overall Time Constant For RMS measurements, the Overall Time Constant
parameter sets the 3dB bandwidth (Hz) for the digital
filtering used to calculate the Overall Value. The
3dB bandwidth is roughly equal to 1 / (2
π
x Overall
Time Constant). The greater the Overall Time
Constant, the slower the response of the measured
Overall Value to change in the input signal.
The lesser value of the Overall Time Constant will
result in a noisier measurement with a fast response
time. A greater value of the Overall Time Constant
will result in a smoother, more accurate
measurement with a slower response time.
Response time is approximately 3X Overall Time
Constant.
For True Peak and True Pk- Pk measurements, the
Overall Time Constant sets the decay rate of the
peak detection meter. The greater the Overall Time
Constant, the slower the Peak is decayed.
Enter a value greater than 0 (zero).
Recommended Values:
The recommended values are
appropriate for a typical 50/60Hz
machine, and may need to be adjusted
depending on the application.
High Pass
Filter
Overall Time
Constant
3Hz, RMS 1.0 sec
3Hz, Pk 2.0 sec
10Hz, RMS 0.5 sec
10Hz, Pk 1.0 sec