Condition Monitoring - XM-120 & 121 Dynamic Measurement Modules

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XM-120 & 121 Dynamic Measurement Modules

120 & 121 Dynamic Measurement Modules

The XM^® series from Rockwell Automation is the world’s first machine monitoring and protection system designed as a distributed network of modules deployed on an open standard industrial bus.

The XM-120 (Standard) and the XM-121 (Low Frequency) Dynamic Measurement Modules are intelligent 2-channel general-purpose monitors that support measurements of dynamic inputs such as vibration, pressure and strain. The modules built-in tachometer makes them particularly well suited for monitoring shaft, casing and pedestal vibration in rotating equipment. The two modules are identical except for their high pass filter selections and in that the XM-120 also supports shaft eccentricity monitoring when its alternate XM-120E firmware is loaded.

Inputs accepted include eddy current probe, standard integrated Electronics Piezo Electric (IEPE) accelerometer, or any voltage output measurement device such as a velocity or pressure transducer. In addition to vibration inputs, the modules accept one tachometer input to provide speed measurement and order analysis functions.

Both modules employ a 24-bit A/D converter which provides unparalleled resolution, making them ideally suited for detecting machinery problems. Virtually any fault that manifests itself through changes in the magnitude or phase of vibration can be detected by the advanced signal processing capabilities of the XM-120 & XM-121 Dynamic Measurement modules. These include most mechanical and electrically induced faults such as unbalance, bearing wear, rotor cracks and rubs, instabilities such as oil whirl, pre-load conditions / misalignment and anti-friction bearing defects.

With two 4-20mA outputs and a single onboard relay, expandable to five, and an integral tachometer, the XM-120 and XM-121 modules offer a complete monitoring system in a small, simple, easily installed, easily maintained package.

The XM-120 and XM-121 modules can operate stand alone, with no interface to higher-level control systems or interactive user interfaces. They can also be deployed on a standard or dedicated DeviceNet network where they can provide real-time data and status information to other XM modules, PLC’s, DCS and Condition Monitoring Systems.

Configuration can be performed either locally or remotely via the DeviceNet network. Local configuration is provided by a simple, intuitive Serial Configuration Utility executing on a PC connected to the modules serial communications port. Remote configuration can be performed from any networked PC executing either any standard DeviceNet configuration software, or the XM specific configuration tool included in RSI’s RSMACC EOL software system.

Selecting which module, the XM-120 or XM-121, is appropriate for an application is dependent on consideration of the minimum frequency of interest, the types of sensors applied and any integration requirements. Typically the minimum frequency of interest will be about one third the normal operating speed of the machine, unless it is important to monitor the machines behavior during startup or coastdown. When measuring low frequency vibration it is essential that the sensor used be rated below the minimum frequency of interest. Otherwise the sensor may introduce significant noise possibly resulting in erroneous, or misleading, data. And if the signal must be integrated then special attention to the sensor quality and high pass filter selection must be made to insure the minimum of noise introduced to the system as only a small amount of noise, at low frequencies, can result in a dramatic reduction in the quality and capability of integrated measurements.

Specifications

Communications

DeviceNet:

Standard DeviceNet protocol for all functions
NOTE: The XM-120/121uses only the DeviceNet protocol, not power. Module power is provided independently.
Available Electronic Data Sheet (EDS) file provides support by most Devicenet compliant systems
Baud rate automatically set by bus master to 125kb, 250kb or 500kb
Configurable I/O Poll Response size (bytes) and Assembly (6 to choose from) helps optimize space utilization within users scanner input tables

Side Connector:

All XM measurement and relay modules include side connectors that allow interconnecting adjacent modules thereby simplifying the external wiring requirements. The Interconnect provides primary power, DeviceNet communication and the circuits necessary to support the XM-441 Expansion Relay module.

Serial:¬

RS-232 via mini-connector or terminal block
Baud rate auto baud to 19200

¬ Local configuration via Serial Utility Program.

Inputs

2 Channels of:

Eddy current transducer signals
Accelerometer signals
Voltage signals from any dynamic measurement device, such as a velocity or pressure transducer

Transducer Power:

Constant voltage (-24V dc)¬
None (voltage input)

¬ Tachometer may be powered, constant voltage, or configured as voltage input.

Voltage Range:

Selectable in software as 0 to ±20V (min) 40Vmax. peak-to-peak

Sensitivity:

User configurable in software

Input Impedance:

>100K

Tachometer

1 Tachometer Input:

±25V (50V max. peak to peak)
1 to 50,000 events per revolution

Input Impedance:

120k minimum

Speed/Frequency Range:

1 to 1,200,000 RPM
0.0167 to 20,000Hz

Speed Measurement Error:

1 to 12,000 RPM +/- 1 RPM
12,001 to 120,000 RPM +/- 6 RPM
120,001 to 1,200,000 RPM +/- 50 RPM

Outputs

4-20mA Outputs:

2 isolated outputs, one per channel
300 W max load

Buffered Outputs:

Each output is independently programmed to represent any measured parameter, from either channel

1 active buffer per vibration input channel
Resistive buffer for tachometer

Indicators

7 LEDs:

Module Status - red/green
Network Status - red/green
Channel 1 Status - off/yellow/red
Channel 2 Status - off/yellow/red
Tachometer Status - off/yellow/red
Eccentricity - off/yellow
Relay - off/red

Signal Conditioning

Sampling Modes:

Asynchronous
Synchronous

Frequency Range:

1 Hz to 20 kHz

Resolution:

A/D Conversion: 24 bits
Dynamic Range: >80dBfs (0.01% fs), -90dBfs (typical)
FFT Lines / Waveform block size
- 100 / 256
- 200 / 512
- 400 / 1024
- 800 / 2048

Amplitude Range:

Dependent on sensitivity

Integration:

Two levels provided, first in hardware, second in firmware.

Averaging:

Any number of averages may be specified. If sampling mode is:

Asynchronous: Averaging will be done on the spectra.
Synchronous: Averaging will be performed on the time waveforms.

Low Pass Filters:

Independently configured per channel:

Spectra FMAX: 10 Hz - 20 kHz
Optional Overall measurement LP filter: 200 Hz - 20 kHz; Roll Off: -24 dB per octave

High Pass Filters:

Independently configured per channel:

XM-120:
- Integration OFF: 1, 5, 10, 40, 1000 Hz; Roll Off: -30 dB per octave for the 1 Hz HPF, otherwise -24 dB per octave
- Integration ON: 5, 10, 40, 1000 Hz; Roll Off:
XM-121:
- Integration OFF: 0.2, 0.8, 2, 4, 23.8 Hz;Roll Off: 30 dB per octave for the 0.2 Hz HPF, otherwise 24 dB per octave
- Integration ON: 0.8, 2, 4, 23.8 Hz; Roll Off:

Units:

g		mm/s
um		psi
ips		mils
volt		Pa

Complex Data

Spectra (synchronous or asynchronous)
Time Waveform (synchronous or asynchronous)
Simultaneous Time Waveforms (synchronous)

Measured Parameters

Overall:

RMS
Peak (true or calculated)
Peak to Peak (true or calculated)

4 Bands per Channel:

Limits defined in frequency or order Domain. Bands may overlap. Calculated Value:

Overall in band
Max peak in band

Gap (or transducer bias voltage)

Speed

Acceleration (RPM/min)

Orders:

Magnitude: 1x, 2x, 3x
Phase: 1x, 2x

Not 1x

SMAX Magnitude and Phase

Sum Harmonics:

Sum Harmonics is the sum of all harmonics from a user defined first order to the maximum order in the spectra.

Data Buffers

Trend Buffer:

Stores a set of records containing measured parameters in response to a trigger event.

Trend Record: 1 to 16 parameters
Trend Interval: 1 to 3600 seconds
Trigger: The trend is saved when a specified relay actuates, or on command from an XM-440, host or controller.
Capacity: 170 to 2048 records depending on the number of parameters stored.

Trip Spectra or Time Waveform:

The current time waveforms or spectra are saved upon the same trigger event defined for the Trend Buffer (above).

Speed Buffer:

Stores a startup/coast-down trend of measurement parameters in response to changes in speed.

Su/Cd Record: 1 to 16 parameters
Su/Cd Interval: 1 to 3600 RPM
Trigger: Records are sampled while speed is between user specified minimum and maximum values.
Sampled while speed is increasing only during startup.
Capacity: 113 to 512 records depending on the number of parameters stored.
Su/Cd buffer may be latched to preserve the initial trip data in the event of subsequent trips.

Alarms

Number:

16 alarm and danger pairs

Alarmed Parameters:

Any measured parameter

Operators:

Greater than
Less than
Inside Range
Outside Range

Hysteresis:

User defined

Startup Inhibit/Set Point Multiplication:

Period: 0 to 1092 minutes in 0.1 min increments
Inhibit/multiplication function:
- Multiply by 2
- Multiply by 3
- Disarm

Inhibit/multiplication initiated by:

Front terminal SPM circuit closure
DeviceNet command
Inhibit/multiplication terminated by:
Expired timer
Front terminal SPM circuit open
DeviceNet command

Speed Inhibit:

A speed range may be specified for each alarm. The alarm is disabled when the speed is outside of the range.

Relays

Number:

Single on-board relay, two sets of contacts – DPDT (2 Form C), plus
Four virtual relays or
Four additional relays when linked to an XM-441 Expansion Relay module.

Onboard Relay Rating:

Max. Voltage = 120 Vdc, 125 Vac
Max. Current = 3.5 A¬
Min. Current = 0
Max. Power = 60 W, 62.5 VA
UL Rating:
- 120 Vac @ 0.5 Amps resistive
- 110 Vdc @ 0.3 Amps resistive
- 30 Vdc @ 1.0 Amps resistive

¬ Max current is up to 40°C, then derates to 2A at 65°C. For Expansion Relay Rating refer to XM441 Technical data sheet ENMON-TD441A-EN-P

Failsafe:

Normally energized (failsafe), or
Normally de-energized (non-fail-safe)

Latching:

Latching, or
Non-latching

Time Delay:

0 to 25.5 seconds in 100msec increments.

Voting Logic:

Single or paired "And" or "Or" logic applied to any alarms.

Reset:

Local reset switch on top of module
Remote reset switch wired to terminal base
Digital reset command via serial or DeviceNet interface

Activation On:

Alarm Status
- Normal
- Alert
- Danger
- Disarm
Transducer Fault
Module Fault
Tachometer Fault

Max Speed Capture

The XM-120/121 retains the value of the highest speed observed since the module was powered up or since the "max speed" value was manually reset.

Non-Volatile Configuration

A copy of the module configuration is retained in nonvolatile memory from where it is read upon power up.¬

¬ The configuration stored in Non-Volatile memory can only be deleted by module-reset command sent via the serial interface, using the Serial Configuration Utility, or via DeviceNet from any compliant software application.

Power

Module:

21.6 - 26.4Vdc

Consumption:

Max: 300mA

Typical: 175mA

Heat Production:

Max: 7 Watts (24 BTU/hr)

Typical: 4 Watts (14 BTU/hr)

Transducer:

Isolated 24V DC, user configurable with wiring

Redundant Power: All XM Measurement and Relay modules support redundant power. Each module includes redundant power inputs on its terminal base.

Approvals

CE, C-Tick, ODVA
CSA Class I, Div 2, Groups A, B, C,
D
UL
EEX

Environmental

Environmental
Operating Temperature	-20 to +65ºC (-4 to 149ºF)
Storage Temperature	-40 to +85ºC (-40 to 185ºF)
Relative Humidity	95% non-condensing

Conformal Coating

All printed circuit boards are conformal coated:

Per material specifications MIL-I-46058C / IPC-CC-830
In accordance with IPC-A-610C

Physical

In accordance with IPC-A-610C.

Dimensions:
Height	3.8in(97mm)
Width	3.7in(94mm)
Depth	3.7in(94mm)

Ordering Informaton

The XM-120E firmware is included on the CD distributed with every XM-120 Standard Vibration Module. Users need only order a standard XM-120 and load the provided XM-120E firmware during configuration.

Cat. No.	Description
1440-VST02-01RA	XM-120 Standard Dynamic Measurement Module¬
1440-VLF02-01RA	XM-121 Low Frequency Dynamic Measurement Module¬
1440-TB-A	Terminal Base A for XM-12x
1440-SCDB9FXM2	XM Serial Communications Cable

¬ *Requires Terminal Base A*