Rockwell Automation 1440-VAD02-01RA XM-123 Aeroderivative Module - Manual (Page 67)

Publication GMSI10-UM003D-EN-P - May 2010
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Tachometer Signal Processing Parameters
IMPORTANT
The tachometer is required for the tracking measurement
and the speed measurement.
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.
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.
Trigger Hysteresis The amount of hysteresis around the trigger
threshold. In Auto Trigger mode, the value entered is
a percentage of the peak-to-peak input signal. This
value can range from 0 to 50%.
In Manual Trigger mode, the value entered is a
voltage level. The hysteresis voltage is added to or
subtracted from the threshold voltage to determine
the hysteresis range. The minimum value is 0.12
volts.
% in Auto Trigger mode
Volt in Manual Trigger mode
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