Tachometer signal processing parameters – Rockwell Automation 1440-VLF02-01RA XM-121 Absolute Shaft Module User Manual
Page 62

Publication GMSI10-UM014D-EN-P - May 2010
54 Configuration Parameters
Tachometer Signal Processing Parameters
IMPORTANT
The Absolute Shaft module requires the tachometer to
track the machine speed (tracking filter) and to calculate the
1X measurements.
If you are not using the tachometer channel, set the Pulses
Per Revolution to zero. This will disable the tachometer
measurement, and prevent the module from indicating a
tachometer fault.
Tachometer Signal Processing Parameters
Parameter Name
Description
Values/Comments
Pulses Per Revolution
The number of tachometer signal pulses per
revolution of the shaft (number of gear teeth). This
setting is useful if a proximity probe located over a
gear or shaft with a multi-toothed speed sensing
surface is used to generate the input signal.
Enter zero if you are not using the
tachometer channel to disable the
tachometer measurement.
Note: When pulses per revolution is
greater than 1, the module will not
consistently synchronize to the same
pulse, and the phase measurement
may change if the module’s
synchronizes on a different pulse.
Important: The tachometer signal is
required (Pulses Per Revolution set
to 1 or more) for the speed and 1X
measurements.
The input tachometer signal is multiplied by this
value to obtain the measured speed.
This value must be greater than zero.
Fault Time-Out
The number of seconds the module should wait after
the last valid tach pulse before it indicates a
tachometer fault.
Enter a value from 1 to 64 seconds.
Sets the trigger mode. In Auto Trigger mode, the
minimum signal amplitude for triggering is 2 volts
peak-to-peak and minimum frequency is 6 CPM (0.1
Hz).
In Manual Trigger mode, the value entered in
Trigger Threshold is used as the trigger point.
Minimum signal amplitude for triggering is 500
millivolts peak-to-peak and minimum frequency is 1
CPM.
XM Configuration
Utility
EDS File
Speed Multiplier
Tach
Multiplier
XM Configuration
Utility
EDS File
Auto Trigger
Trigger
Mode
XM Configuration
Utility
EDS File
Check = Auto Mode
Auto
Clear = Manual
Mode
Manual