Transcript Measurement - Rockwell Automation Knowledgebase

What are all these
parameters???
An Explanation of the
XM120/XM121 Program
Parameters.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Channel Description Field
This field allows the customer to give a descriptive name to a channel, tachometer,
alarm, or relay depending on the parameter. The name only appears on the
specified channel’s tab. The name has a maximum of 18 characters.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
IEPE Power Supply for Accelerometers
Controls whether to provide standard accelerometer (IEPE) power to the
transducer. Select the parameter when an IEPE accelerometer is wired to the
channel. Clear the parameter when any other type of transducer is wired to the
channel. If channel is unused, clear the parameter to avoid transducer fault.
IEPE : Integrated Electronic Piezo-Electric
Check this box if you are using the
following:
9000A, 9100, 9200, 9300, 9100VO
Do NOT check this box is you are using:
2100 Non Contact System
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Transducer Sensitivity
Sensitivity is the amount of voltage output the transducer
produces for a defined amount of force or movement the
transducer senses. The sensitivity value is included with
the transducer’s documentation or it may be imprinted on
the side of the transducer. Enter the sensitivity of the
transducer in millivolts per Eng. units.
Some Standard Sensitivities:
9000A, 9100, 9200, 9300 = 100 mV/g
9100VO = 100 mV/ips (3.94 mV/mm/sec)
2100 (8mm ) = 200 mV/mil (7.87 V/mm)
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Transducer Engineering Units
Defines the physical units the transducer senses. Example: Accelerometers
measure g Forces; Velocity transducers measure the velocity of movement of a
machine; Non Contact Probes measure the displacement between the tip of the
probe and the machine surface. The transducer calibration certificate displays the
Units of measure.
Some Standard Units of Measure:
9000A, 9100, 9200, 9300 = g
9100VO = ips (mm/sec)
2100 Non Contact System = mil (um)
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Transducer Fault Low Value
The Transducer Fault Low voltage is an indication point that the transducer output
is no longer viable when the transducer bias voltage drops below (more negative)
then this value.
If a channel is unused, set the Transducer Fault Low voltage to -18 volt to avoid
transducer fault. This parameter appears on the Channel 1, Channel 2, and
Tachometer tabs.
Some Standard Fault Low Settings:
9000A, 9100, 9200, 9300 = +4.0 VDC
9100VO = +4.0 VDC
2100 (8mm probe tip) = -20VDC
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Transducer Fault High Value
The Transducer Fault High voltage is an indication point that the transducer output
is no longer viable when the transducer bias voltage goes above (more positive)
then this value.
If a channel is unused, set the Transducer Fault Low voltage to -18 volt to avoid
transducer fault. This parameter appears on the Channel 1, Channel 2, and
Tachometer tabs.
Some Standard Fault High Settings:
9000A, 9100, 9200, 9300 = +20.0 VDC
9100VO = +20.0 VDC
2100 (8mm probe tip) = -4.0VDC
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Transducer DC Bias Time Constant
The DC Bias Time Constant is the digital filter that strips away the AC vibration
signal and gives us the DC bias voltage of the transducer. The filter equation is
1/(2π x DC Bias Time Constant). The response time of the filter to a step change in
the input is approximately 2.2 * the time constant (seconds). Example: If the Time
Constant is set for 2 seconds then it will take about 2.2 * 2 second time constant =
4.4 seconds for the output value to catch up to a step change in the input. This
parameter appears on the Channel 1, Channel 2, and Tachometer tabs. See table
for typical values.
Time Constant for most applications: 1.769
Time Constant for slow moving machines
like Hydro Turbines: 4.0 may be more
appropriate.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Transducer Full Scale setting
This value is used to determine the analog hardware gain settings. Setting the full
scale to a larger value allows the channel to handle larger input signals without
saturating or clipping. Setting it to a smaller value generates greater amplitude
resolution. Setting the value too small could create signal clipping in the hardware
which may cause false alarms and spikes in the measured value. This setting is
also dependent on the filter settings.
The XM120/121 manual has a Guidelines for setting the Full Scale section to
assist in setting this value. Note: The values in the Guideline must be used. There
are no values in between the values listed.
The Sample Configuration files have this
value preset to handle a large input signal.
This is done to avoid circuit saturation. If
higher resolution is needed, please follow
the Guidelines for setting the Full Scale.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Transducer Auto Full Scale button
The Auto Full Scale button assists in setting the Full Scale in applications using the
2100 Non Contact systems. This button is not to be used when accelerometers or
velocity transducers are connected to the XM.
To use this feature please refer to the XM Users manual. In most applications the
Guidelines for setting the Full Scale in the user manual should be used instead of
this feature.
In most applications use the default
value in the sample configuration file
or refer to the Guidelines for setting
the Full Scale in the user manual.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Signal Processing Output Data Unit
Select the units of vibration you want to output. The selections depend on the Eng.
units selection. See chart below.
Parameter appears on Channel 1 and Channel 2 tabs.
Eng. Units
Output Data Unit Options
g
g
ips
mil
mm/sec
In most applications for:
9000A,9100, 9300: ips (mm/s)
9100VO: mils (mm)
2100 Non Contact: mils (um)
µm
ips or mm/sec
ips
mil
mm/sec
µm
mils or µm
mils
µm
Volt
volt
Pa or psi
Pa
psi
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Signal Processing High Pass Filter
The high pass filter attenuates frequencies below the selected filter corner and
passes frequencies which are above the filter corner. This filter is applied to the
signal before the A/D, so it affects all the measurements.
For integrated measurements, the lowest frequency selection for the high pass
filter is not available.
The XM120 and XM121LF have different selections.
This parameter appears on Channel 1 and Channel 2 tabs.
Selection of this value is normally based on
the machines running speed.
Examples:
Machine speed: 1500 RPM, select 10 Hz.
Machine speed: 750 RPM, select 5 Hz.
Machine speed: 120 RPM, select 0.8 Hz.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Signal Processing Sampling Mode
There are two ways the vibration signal can be sampled, Asynchronous, which is not
time sequenced with the machine’s running speed and Synchronous, which is time
sequenced with the machine’s running speed. The sampling mode only affects the
spectral derived measurements (bands, vectors, not 1x, sum-harmonics).
In most applications choosing the mode comes down to answering the following
question: Is there a tachometer input from the machine?
No: Select Asynchronous.
Yes: Select Synchronous.
Function
Asynchronous
Synchronous
Sample Rate
Set by internal
hardware circuit.
Set by machine shaft
running speed.
Spectrum &
FMAX
Specified in HZ or
CPM
Specified in Orders
Frequency Bands
Hz or Orders (if
tachometer is
present)
Hz or Orders
Measurement
Mode
Standard
Preferred for
variable speed
machines and turbo
machinery
SMAX Magnitude
& Phase
NA
Requires
Synchronous Mode
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Signal Processing Internal Gear Teeth
This field is active only if a Tachometer input is supplied AND synchronous
sampling mode is selected.
This field along with the External Gear Teeth field creates the ratio number across
a gear box for speed and phase measurements through out a machine train from a
single speed input signal.
This would be the number of teeth on the buried shaft gear.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Signal Processing External Gear Teeth
This field is active only if a Tachometer input is supplied and synchronous
sampling mode is selected.
This field along with the Internal Gear Teeth field creates the ratio number across
a gear box for speed and phase measurements through out a machine train from
a single speed input signal.
This would be the number of teeth on the external shaft gear.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Measurement Options Signal Detection
The detection method performed on the processed analog signal to produce the
Overall Vibration Value displayed. The Chart below lists the typical settings for
different Input Transducers and Output data units.
Note: When changing the Signal Detection, make certain to update the Overall
Time Constant value.
Input Transducer
Output data
units
Signal Detection
9000A, 9100,
9300
Accelerometers
Acceleration
(g’s)
Calculated Peak
9000A, 9100,
9300
Accelerometers
Velocity
(in/sec)
Calculated Peak
9000A, 9100,
9300
Accelerometers
Displacement
(mils)
Calculated Peak to Peak.
9100VO Velocity
Transducer
Velocity
(in/sec)
Calculated Peak
9100VO Velocity
Transducer
Displacement
(mils)
Calculated Peak to Peak
2100 Non
Contact Eddy
Current Probes
Displacement
(mils)
True Peak to Peak.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Measurement Option Overall Time Constant
The Overall Time Constant parameter sets the filtering used to calculate the Overall
Value.
The standard values used are listed in the chart below.
Measurement
High Pass
Filter
Overall
Time
Constant
N/A
1.5
RMS, Calculated Peak,
Calculated Peak to Peak
0.2Hz
0.8
RMS, Calculated Peak,
Calculated Peak to Peak
0.8Hz
0.2
RMS, Calculated Peak,
Calculated Peak to Peak
1Hz
0.16
RMS, Calculated Peak,
Calculated Peak to Peak
2Hz
0.08
RMS, Calculated Peak,
Calculated Peak to Peak
4Hz and
above
0.045
True Peak or True Peak-toPeak
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Measurement Option-Overall Damping Factor
This parameter is used in conjunction with the Overall Time Constant in calculating
the Vibration Overall value. For the most accurate response leave the damping
factor at 1.0 (critical damping). If a faster response is required then set the damping
factor to 0.707 - but keep in mind this will result in overshoot / undershoot of the
actual value till the entire Overall Time Constant settling time has transpired.
Default: 1.0 or 0.99.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Measurement Options Overall Filter
A Low Pass filter used to remove unwanted high frequencies.
None: No overall filter.
Low pass: remove frequencies above the Low pass filter value for overall
measurements.
Note: This only affects the Overall value, not the FFT & other measurements.
Default: Low Pass Filter
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Measurement Options Low Pass Filter
The range of values you can enter is from 200 to 20,000Hz.
Sets the frequency above which the input signal will be significantly attenuated.
This value is used only when the Overall Filter is set to “Low Pass Filter.”
Default: 2000 Hz
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Measurement Options
Order of Sum Harmonics
This analysis feature uses the machine running speed as a reference point to
establish the first order (1X). The harmonics of this running speed are whole
number multiples of the running speed.
Example: Machine running speed is 1800, the 2nd harmonic (2X) is 3600.
This feature adds up all the energy of the running speed harmonics up to the FMAX
starting with the number entered.
Note: FMAX is set in the Spectrum/Waveform dialog. The tachometer must be
enabled, a tachometer signal must be present. Sampling Mode can be either
Asynchronous or Synchronous.
Default: 4
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Measurement Option Spectrum/Waveform
Displays the Spectrum/Waveform dialog box to configure the spectrum and
waveform measurements for the XM-120, XM-121, or XM-122 modules. There are
two instances of the spectrum/waveform parameters, one for each channel.
Note: Each Channel must be configured.
Default: Set both channels to
the same settings for most
applications.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Spectrum/Waveform - FMAX
Sets the maximum frequency or order for the spectrum measurement. You can enter
any FMAX. The module automatically uses the next higher supported maximum
frequency. The Sampling Mode parameter determines whether the measurement is
frequency or order. This parameter appears on Channel 1 and Channel 2 tabs.
Single integrated/non-integrated
measurements (Hz)
Double integrated
measurements (Hz)
10 to 5000
10 to 5000
6250
6250
7500
9375
8000
18750
Default: 2000 Hz for Asynchronous
and 40 Orders for Synchronous
applications.
9375
10000
12500
15000
18750
20000
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Spectrum/Waveform – Number of lines
The number of lines in the spectrum measurement. This determines the frequency
or order resolution of the spectrum measurement.
Note: See chart below for valid settings. This parameter appears on Channel 1 and
Channel 2 tabs.
Number of Lines
Default: 800
FMAX
100
200
400
800
4
√
√
√
√
5
√
√
√
√
√
√
√
√
√
√
√
√
8
10
√
16
20
√
√
√
√
25
√
√
√
√
32
40
√
√
√
√
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Spectrum/Waveform - Period
Displays the total time period in seconds or cycles to take the waveform
measurement.
Note: The more lines of resolution (the greater the resolution) the longer it takes to
make the waveform measurement.
The value is in seconds if Sampling mode is set to “Asynchronous.” The value is in
cycles if Sampling mode is set to “Synchronous.”
This is a displayed value only.
Do not enter a value.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Spectrum/Waveform – Number of Points
Displays the number of points (samples) in the waveform measurement.
Note: The chart below shows the correlation between Lines of Resolution and
Number of Points.
Lines of Resolution
Number of Points
100
256
200
512
400
1024
80
2048
If you have entered a value for
Lines of Resolution, then this is just
a displayed value only. No entry is
required.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Spectrum/Waveform – Window Type
When waveforms are digitally sampled some discontinuities can be created in the
data. Applying a “Window” is a mathematical way to remove these discontinuities.
Each “Window” type handles these discontinuities differently and creates a slightly
different pattern of spectral display.
Note: This parameter appears on Channel 1 and Channel 2 tabs.
Type
Description
Rectangular
Also know as Uniform. Give poor peak amplitude,
good peak frequency accuracy. Useful for impulsive
or transient data.
Hanning
Used in predictive maintenance. Gives fair peak
amplitude accuracy, fair peak frequency. Useful for
random type data where energy is at all frequencies.
Hamming
Gives fair peak amplitude accuracy, fair peak
frequency accuracy. Similar to Hanning.
Flat Top
Also called Sinusoidal window. Gives good peak
amplitude accuracy, poor peak frequency accuracy
for data with discrete frequency components.
Kaiser Bessel
Gives fair peak amplitude accuracy, fair peak
frequency accuracy.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Default : Hanning
Spectrum/Waveform – Number of Averages
By using the averaging feature it becomes easy to filter out unwanted signals in
noisy applications
Sets the number of individual data sets to be incorporated into the average
calculation. Setting the value to 1 means no averaging.
Note: Averaging is only applied to the FFT data. Values derived from the FFT, such
as Bands and Order values are not averaged.
Default : One (1)
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Measurement Option – Band Feature
The Band feature allows a user to measure the energy that exists within a user
selectable frequency range. Bands may be configured in either frequency or orders
(if tachometer is present) domain, independent of the Sampling Mode selected.
Example: A machine has a running speed of 1780 RPM. Band 1 could be
configured to measure the energy between 1700 and 1900 CPM (28 - 32HZ). This
band would only display the energy generated at the machine’s running speed.
There are four (4) programmable band measurement parameters for each channel.
Default setting:
For traditional overall vibration
monitoring: No settings required.
For analytical vibration monitoring:
Knowledge of the machine and vibration
concepts is required. If no local vibration
analyst is available, Rockwell Automation
provides as a paid for service vibration
analysts who can assist in defining
bands.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Measurement Option
Band Feature - Measurement
The measurement (or calculation) performed to produce the Band Value.
• Band Overall - The Band Value is the square root of the sum of the squares (RSS)
of the amplitude values for the bins that make up the band. If the band includes all of
the spectrum bins then the Band Value is equivalent to the digital or RSS overall
value.
• Max Peak in Band - The Band Value is equal to the maximum bin amplitude found
within the band.
Default: Band Overall
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Measurement Option
Band Feature - Minimum Frequency
The lowest frequency of interest for this band measurement.
Note: If the Sampling Mode was set to “Synchronous” this value can be in “Orders”
of the machine running speed.
The Frequency ranges for each band may overlap.
Units for this value can be in Hz, or CPM and if Synchronous sampling was
selected, Orders.
Default: For Minimum Frequency
see analyst for advice
For Units: CPM
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Measurement Option
Band Feature - Maximum Frequency
The highest frequency of interest for this band measurement.
Enter a value greater than or equal to the Minimum Frequency.
Note: This value must be less than or equal to FMAX, set in the
Spectrum/Waveform Selection.
The Frequency ranges for each band may overlap.
Repeat the same process for Bands 2,3 & 4.
Default: For Maximum Frequency
see analyst for advice.
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Tachometer – Pulses Per Revolution
The number of voltage pulses coming from the speed transducer for each shaft
rotation.
Examples:
1) If the speed transducer is over a shaft keyway then there will be a voltage
pulse each time the keyway passes under the speed transducer. This
normally generates one voltage pulse per shaft rotation.
2) If the speed transducer is over a gear then there will be a voltage pulse each
time a gear tooth passes under the speed transducer.
Default:
No speed transducer: Zero (0). This
disables the Tachometer reading.
Keyphasor transducer installed: One (1)
Speed transducer looking at a gear: Must
get number of gear teeth from Customer.
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Tachometer – Fault Time Out
Fault timeout is the length of time the tachometer signal must be missing before
causing a tachometer fault. You can enter from 1 to 64 seconds.
Examples for reference:
Critical Steam Turbine speed: One (1) second
Hydro Turbine speed: Thirty (30) seconds
Default: One (1) second
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Tachometer – Auto Trigger
There are two ways the voltage pulse can be measured:
1) Auto trigger mode. This is designed to account for small changes in signal
amplitude and bias without changing the trigger position or losing the tachometer
reference.
2) Manual mode. The user sets the voltage level, hysteresis, and slope
Concerns when setting the trigger level:
1) Make sure the reference point threshold will always be crossed. Allow for some
mechanical drift over time when setting this value.
2) Compensate for DC bias and pulse amplitude variations that can happen over the
machine’s operating speed and shaft lateral movements.
Default: Auto Trigger
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Tachometer – Trigger Hysteresis
Trigger Hysteresis – The voltage window which must be exceeded before the XM
sees a change in the direction of the pulse.
1) 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%.
2) 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.
Default:
Auto Trigger mode: 2 %
Manual Trigger mode: 1 Volts
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Tachometer –Trigger Threshold
This setting is only active in the Manual Trigger Mode.
When this voltage level is exceeded the XM will register the signal as a valid pulse.
The Trigger Hysteresis voltage is added to and subtracted from this voltage to set up
the voltage window the input pulse must exceed to be recognized as a valid pulse.
Valid values are from +16 to -16 volts dc.
Default:
2100 Proximity probe: -12 Volt
Hall Effect Sensor: 2.5
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Tachometer – Trigger Slope
This setting is only used in Manual Trigger Mode.
This setting defines the direction the voltage pulse must go to be accepted as a valid
signal to trigger from.
There are two options: Positive or Negative
Default:
2100 Proximity probe: Negative
Hall Effect Sensor: Positive
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Tachometer
Exponential Averaging Time Constant
This is the digital filter used to calculate the Speed value. The filter bandwidth is
roughly equal to 1/(2π x Exponential averaging time constant). The greater the value
entered, the longer time it takes to respond to a measured Speed value change. This
makes the measured Speed value less sensitive to noise in the signal.
Time Constant
(milliseconds
-3dB Frequency
Settling Time
(milliseconds)
5
31.831
11
10
15.9155
22
20
7.9577
44
50
3.1831
110
100
1.5915
220
1200
0.1326
2640
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Default: 100
Alarms - Number
There are 16 user configurable alarms in the XM-120/121.
The alarms are not restricted to a channel or measurement parameter.
The “Number” drop down box allows the user to select each of these alarms
individually. To activate an alarm select a number from 1 to 16 and then click in the
Enable box.
Default: For most applications a minimum of
4 alarms are set. The Overall vibration for
both channels and the transducer bias (gap)
voltage to track the health of the transducer
Alarm 1 – Is used for Ch1 Overall
Alarm 2 – Is used for Ch2 Overall
Alarm 3 – is used for Ch1 Gap
Alarm 4 – is used for Ch2 Gap
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Alarms - Enabling
In the XM120/121 an Alarm can be Enabled or Disabled quickly via the Enable check
boxes.
The value of this feature is seen during commissioning and system trouble shooting.
When a field issue surfaces the user can enable or disable an alarm simply by
clicking on the check box next to the Enable selection.
Note: The Alarm Status is set to “Disarm” when the alarm is disabled. The Relay
Current Status is set to “Not Activated” when the relay is disabled.
Default: For most applications a minimum
of 4 alarms are set. The Overall vibration
for both channels and the transducer bias
(gap) voltage to track the health of the
transducer
Alarm 1 – Is used for Ch1 Overall
Alarm 2 – Is used for Ch2 Overall
Alarm 3 – is used for Ch1 Gap
Alarm 4 – is used for Ch2 Gap
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Alarms – Measurement Parameter
This drop down box is used to select the channel and measurement that will be used
to activate the alarm. A maximum of eight alarms can be assigned to any one
measurement.
Selections for the XM120/121:
Channel 1 values: Overall, Transducer Gap
(bias voltage), Bands 1 – 4, 1X, 2X or 3X
Magnitude, 1X or 2X Phase, Sum
Harmonics
Channel 2 values: Overall, Transducer Gap
(bias voltage), Bands 1 – 4, 1X, 2X or 3X
Magnitude, 1X or 2X Phase, Sum
Harmonics
Module values: Speed, Acceleration
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Alarms – Activation Condition
Controls when the alarm should trigger.
Option
Trigger alarm when measurement value is…
Greater than
Greater than or equal to the Alert and Danger threshold
values. The Danger Threshold value must be greater than
or equal to the Alert Threshold value for the trigger to
occur.
Less than
Less than or equal to the Alert and Danger threshold
values. The Danger Threshold value must be less than or
equal to the Alert Threshold value for the trigger to occur.
Inside range
Equal to or inside the range of the Alert and Danger
threshold values. The Danger Threshold (High) value
must be less than or equal to the Alert Threshold (High)
value AND the Danger Threshold (Low) value must be
greater than or equal to the Alert Threshold (Low) value
for the trigger to occur.
Outside
range
Equal to or outside the range of the Alert and Danger
threshold values. The Danger Threshold (High) value
must be greater than or equal to the Alert Threshold
(High) value AND the Danger Threshold (Low) value must
be less than or equal to the Alert Threshold (Low) value
for the trigger to occur.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Default:
Overall Alarm: Greater
than
Gap: Outside range
Alarms – Alert Threshold
There can be one or two Alert Thresholds. This is based on the Activation Condition.
If Greater Than or Less Than is selected then there is one Alert Threshold. If Inside
Range or Outside Range is selected then there are two Alert Thresholds.
Alert Threshold (High): This parameter is the greater threshold value.
Alert Threshold (Low): This parameter is the lesser threshold value.
Default:
These values can be specified by the
customer, the machine builder or in house
vibration analyst. These values can be
affected by machine installation, planned
usage, defined maintenance schedules
and personnel or process protection
requirements. Rockwell Automation will
assist but can not define these values.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Alarms – Danger Threshold
There can be one or two Danger Thresholds. This is based on the Activation
Condition. If Greater Than or Less Than is selected then there is one Danger
Threshold. If Inside Range or Outside Range is selected then there are two Danger
Thresholds.
Danger Threshold (High): This parameter is the greater threshold value.
Danger Threshold (Low): This parameter is the lesser threshold value.
Default:
These values can be specified by the
customer, the machine builder or in house
vibration analyst. These values can be
affected by machine installation, planned
usage, defined maintenance schedules and
personnel or process protection
requirements. Rockwell Automation will
assist but can not define these values.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Alarms - Hysteresis
The amount the measured value must move below the threshold before the alarm
condition is cleared. For example, Alert Threshold = 120 and Hysteresis = 2. The
alarm (alert) activates when the measured value is 120 and will not clear until the
measured value is 118. The Alert and Danger Thresholds use the same hysteresis
value. For the Outside Range condition, the hysteresis value must be less than Alert
Threshold (High) – Alert Threshold (Low).
Default:
Initial value set to 2% of the Alert Threshold
value. When the machine is running notice
how much the Overall vibration value is
changing. If it is less then 2% of the Alert
Threshold, then leave the 2% value. If it is
more (this can be due to process and other
noise sources, then adjust so it is larger then
the noise level but lower then the difference
between the Alert Threshold and the Danger
Threshold values.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Setpoint Multiplier – Startup Period
The Setpoint Multiplier (SPM) is used to keep the monitor system from going into a
false alarm state during machine start ups and coast downs. Each Alarm has its own
SPM to set. The longest time period programmed will be the time the timer is
engaged. It is advised to set all Startup periods to the same amount of time.
The Startup Period is the length of time that the Threshold Multiplier value is applied
to the Alert and Danger threshold values. The startup period begins when the
Setpoint Multiplier switch is reopened (push button disengaged or toggle switch
flipped to off). Enter a value from 0 to 1092 minutes, adjustable in increments of 0.1
minutes.
Default: 1 minute
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Setpoint Multiplier – Threshold Multiplier
The Threshold Multiplier is the value applied to the alarm thresholds when the
Setpoint Multiplier (SPM) switch is closed. When the SPM switch is opened the timer
is initiated. When the timer expires the Thresholds are returned to their original
values.
Example:
Threshold Multiplier is set to 3, Alert Threshold is 0.6, Danger Threshold is 0.8
When the Multiplier is engaged: Alert Threshold is 1.8, Danger is 2.4
Default: 3
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Setpoint Multiplier–Inhibit Tachometer Fault
During machine maintenance, just before start, and until the speed has increased
sufficiently, a tachometer fault will be signaled due to lack of pulses being observed.
Setting this parameter excludes the zero (no) pulse condition from the tachometer
fault logic thus inhibiting the tachometer fault indication while SPM is active. This
parameter should be selected for machines which are not to be started while a
tachometer fault is indicated.
Note: A tachometer transducer bias out of range state will still cause a tachometer
fault regardless of this parameter status.
Default: Unchecked
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Advanced Alarm – Speed Range Enable
When this feature is enabled then the selected alarm is active only when the
measured speed is within the speed range defined by the Speed Range High and
Speed Range Low. The tachometer must be enabled (Pulses Per Revolution set to 1
or more) and a tachometer signal provided at the tachometer input.
Note: You cannot enable the Speed Range parameter when the alarm Measurement
is set to “Speed.”
Default: Unchecked
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Advanced Alarm – Speed Range Low
The lower end of the machine speed range where the alarm will be active. This
value must be less than the Speed Range High value. This parameter is not used
when Speed Range Enabled is not activated.
Default: No value
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Advanced Alarm – Speed Range High
The upper end of the machine speed range where the alarm will be active. This
value must be greater than the Speed Range Low value. This parameter is not used
when Speed Range Enabled is not activated.
Default: No value
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Relays - Number
Selects the relay to be configured. Relay Number 1 is the on-board relay. Numbers 2
through 5 are either relays on the XM 441 Expansion Relay module (when
connected) or virtual relays. Virtual relays are non-physical relays. Use them when
you want the effect of the relay (monitor alarms, delay, and change status) but do not
need an actual contact closure such as when they are used with a PLC or controller
monitoring the relay status. The Relay Installed parameter indicates whether a relay
is a virtual relay or a physical relay on a module.
Default: No relays are enabled.
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Relays - Enabling
A Relay can be Enabled or Disabled quickly via the Enable check boxes.
The value of this feature is seen during commissioning and system trouble shooting.
When a field issue surfaces the user can enable or disable a relay simply by clicking
on the check box next to the Enable selection.
Note: The Relay Current Status is set to “Not Activated” when the relay is disabled.
Default: No relays are enabled.
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Relays - Latching
When a Relay is enabled it can be set to Latching, which maintains relay closure till
manually or by a digital command reset. If Latching is not selected then the relay will
automatically toggle off when the alarm condition has passed.
Default: Latching is not active.
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Relays – Activation Delay
Enter the length of time the alarm condition must be true before the relay is activated.
This reduces nuisance alarms caused by external noise and/or transient vibration
events. True Peak and True Peak-to-Peak signal detection is more sensitive to
transients and noise. To avoid false relay activations, it is strongly recommended
that the Activation Delay value be set greater than the Overall Time Constant value
when Signal Detection is set to “True Peak” or “True Peak-to-Peak.”
Default: 3 seconds.
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Relays – Activation Logic
Sets the relay activation logic.
 A or B - Relay is activated when either Alarm A or Alarm B meets or exceeds the
selected Alarm Status condition(s).
 A and B - Relay is activated only when both Alarm A and Alarm B meet or exceed
the selected Alarm Status condition(s).
 A Only - Relay is activated when Alarm A meets or exceeds the selected Alarm
Status condition(s).
Default: Since the default has no relays
enabled, this area is grayed out.
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Relays – Activation Logic – Alarm A & B
Selects from the list of the enabled alarms which alarm(s) will activate the relay. The
alarm must be from the same device as the relay. When the Activation Logic is set to
“A and B” or “A or B,” you can select an alarm in both Alarm A and Alarm B. The
system monitors both alarms. When the Activation Logic is set to “A Only,” you can
select an alarm only in Alarm A.
Default: Alarm A & Alarm B: Since the
default has no relays enabled, this area is
grayed out.
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Relays – Alarm Status to Activate On
Sets the alarm conditions that cause the relay to activate. More than one can be
selected.
Status
Activate relay when...
Normal
The current measurement does not cross any alarm
thresholds.
Alert
The current measurement is in excess of the alert
level threshold(s) but not in excess of the danger
level thresholds.
Danger
The current measurement is in excess of the
danger level thresholds.
Disarm
The alarm is disabled or the device is in Program
mode.
Xdcr fault
A transducer fault is detected on the transducer(s)
associated with the selected alarms.
Module
fault
A failure or error is detected in the hardware or in
the configuration, and is preventing proper
operation. Note: Module will not transition to Run
mode if an invalid configuration is loaded
Tacho fault
A transducer fault is detected on the tachometer
associated with the selected alarms. Note: Requires
that the alarmed parameter use the tachometer to
make the specified measurement (ex: 1X uses the
tachometer, OA does not ).
Default: Alarm Status to Activate On:
Since the default has no relays enabled,
this area is grayed out.
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Relays – Relay Installed
Indicates whether the relay is a physical relay or a virtual relay. If the Relay Installed
area has an active check box then the relay is physically there. If the Relay Installed
is grayed out then the relay is virtual.
Default: Relay Installed: Since the
default has no relays enabled, this area
is grayed out.
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Relays – Failsafe Relay
This parameter is only available when the relay is a physical relay in or available to
the module. Failsafe operation means power is applied to the relay coil during
normal operating conditions. Power is removed from the relay coil when an alarm
occurs. This alters the operating definition of the relay contacts.
For non-failsafe operation, the following are true:
• Non-alarm conditions - the N.C. (normally closed) and common terminals are
shorted.
• Alarm conditions - the N.O. (normally open) and common terminals are shorted.
For failsafe operation, the following are true:
• Non-alarm conditions and with power applied to the XM - the N.O. and common
terminals are shorted.
• Alarm or loss-of-power conditions - the N.C. and common terminals are shorted.
Default: Failsafe Relay: Since the
default has no relays enabled, this area
is grayed out.
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4-20mA Outputs – Enable & Measurement
To activate the 4-20mA output function the box next to Enable must be checked.
The XM120 has two user selectable 4-20mA outputs. These outputs can be
configured to deliver the current output for any of the 25 different measurements.
Default: Enable this feature for both
channels.
Top 4-20mA output: Ch1 Overall
Lower 4-20mA output: Ch2 Overall
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4-20mA Outputs – Min & Max Range
Min Range: The measured value which should produce the 4 mA output.
Max Range: The measured value which should produce the 20 mA output.
Notes:
1) The Min Range value does not have to be less than the Max Range Value. If the
Min Range value is greater than the Max Range value, then the output signal is
recognized as being inverted from the input signal.
2) The 4-20 mA output accurately measures 10% beyond the Min and Max Range.
Measured values between Min and Max Range are scaled to produce the correct
value between 4.0 to 20.0mA.
Defaults:
For Velocity measurement:
Min Range: 0 and Max Range: 1.0
For Displacement measurement:
Min Range: 0 and Max Range: 15
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
Triggered Trend and SU/CD Trend
Triggered Trend and SU/CD Trend are normally left un-configured.
The details of these two features are covered in a separate presentation.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.
I/O Data – Change of State Values
Here is the Change of State (COS): Size, Assembly Instance and what data the
COS bytes reflect.
Note: The COS settings cannot be altered.
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I/O Data – Poll Data Size
Poll size shows the number of bytes in the selected Assembly Instance. Decreasing
the size will truncate data from the end of the Assembly structure.
The minimum size is 4 bytes and the maximum size is 124 bytes.
The Poll size should always be a multiple of 4 bytes since the Poll response message
contains real numbers (floats) exclusively.
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I/O Data - Poll Output
Displays the selected Assembly instance used for the Poll response message. Each
Assembly instance contains a different arrangement of the Poll data. The Poll
response message is used by the XM module to produce measured values. It
contains 31 REAL values for a total of 124 bytes of data.
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I/O Data – Custom Assembly
A Custom Assembly lets the user choose what measurements are of interest. This is
especially helpful when Scanner Table space is at a premium. By using the Custom
Assembly the end user can configure the Polled data down to smallest amount of
bytes needed for the application.
Note: The Custom Assembly must be configured before the XM is connected to the
DeviceNet Network and the .DNT file is created.
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Module – Reset Button
The Rest button on the Module tab restores all the device parameters to the factory
default values. This includes the node address and baud rate. The module must be
programmed and placed back into run mode to begin operating again.
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Module – DeviceNet Node Address
This is where the DeviceNet Module address is programmed. Enter a unique node
address (between 0 and 63) for the device.
Note: Every device in a DeviceNet network must have a unique node address.
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Module – DeviceNet Baud Rate
The XM measurement modules (for example, XM-120, XM-121, XM-122 Vibration
modules and XM-320 Position module) are always set to autobaud. These modules
cannot be configured to use a specific baud rate. These XM modules act as slaves
on the DeviceNet network.
Note: The DeviceNet network Primary master should be set for a fixed baud rate.
Example: The XM-440 Master Relay module, which can act as the Primary master
on a DeviceNet network, can be set to a specific baud rate. The XM measurement
modules will sense and set themselves to this fixed baud rate.
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Module – DeviceNet Apply Button
Once the DeviceNet Address has been selected, press this button to program the
new address into the XM module.
Note: If you press this button without changing the node address the module will still
go through the normal reset process.
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Module – Update Firmware Button
Click this button to update the module with new firmware. The Open dialog appears.
Follow the steps to update the device. During the update the module is unable to
perform its normal functions. Do not remove power during a firmware update. If
power is removed the XM may no longer function.
Copyright © 2009 Rockwell Automation, Inc. All rights reserved.