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XM-120E Eccentricity Module

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120E Eccentricity Module

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-120E Eccentricity Module is an XM-120 Standard Vibration Module with alternative, XM-120E,firmware loaded. The XM-120E firmware is included on the distribution CD with every standard XM-120.

Eccentricity is the measure of the amount of bow in a rotor. Rotor bow can be a fixed mechanical bow, or it can be a temporary bow caused by uneven thermal heating or simply by the weight of the rotor (gravity bow). The XM-120E provides four key measurements including the peak-topeak eccentricity value, the instantaneous gap value and the minimum and maximum observed gap values.

Because the XM-120E uses the XM-120 Standard Vibration Module hardware module, many of the specifications of that module are common to the XM-120E, particularly with respect to approvals and its physical and environmental specifications. Refer to the XM-120 & 121 Vibration Module data sheet for details regarding these and other characteristics of the hardware.


Specifications


Communications


DeviceNet:

  • Standard DeviceNet protocol for all functions
    NOTE: The XM-120E uses 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


Serial:¬ 

  • RS-232 via mini-connector or terminal block


¬ Local configuration via Serial Utility Program.

Inputs


2 Channels of:

  • Eddy current transducer signals


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:

  • 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


Frequency Response:

  • Peak-to-peak Eccentricity,
  • Max Gap,
  • Min Gap: 0.0039 to 20 Hz; (0.235 to 1200 cpm)


Accuracy:

  • ±1% of measurement
  • Noise Floor: 8mV RMS
  • Specified at ambient temperature of +25°C (+77°F)


Gap Resolution:

5.2mV


Waveform:

  • Block Size: 256, 512, 1024, 2048
  • Period: 5 to 800 seconds


Amplitude Range:

±21V


Units:

  • mm
  • volt
  • mils

Complex Data

  • Time Waveform (asynchronous)

Measured Parameters


Peak-to-Peak Eccentricity:

The difference between the positive and the negative extremes of the rotor bow in mm or mils.


Gap:

Volts


Min Gap:

Volts


Max Gap:

Volts


Speed:

RPM

Alarms


Number:

2 alarm and danger pairs (one each for the eccentricity measurements)


Operators:

  • Greater than
  • Less than
  • Inside Range
  • Outside Range


Hysteresis:

User defined


Speed Inhibit:

A speed range may be specified for each alarm. When applied, if the speed is outside of the defined range, the alarm is disabled.

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 Vibration Module¬ 
1440-TB-A Terminal Base A for XM-12x
1440-SCDB9FXM2 XM Serial Communications Cable
  
¬ Requires Terminal Base A