Allen-Bradley 1440-SDM02-01RA, User Manual, Page: 80 / 168

80 Rockwell Automation Publication 1440-UM001D-EN-P - September 2016
Chapter 2 Configure the XM-124 Standard Dynamic Measurement Module
Position measurements, including thrust, can be measured in one of three ways:
• Normal - The two sensors are used independently tot perform two
separate position measurements.
• Head-to-head
(1)
- The two sensors are used together, facing each other
on either side of the target, to perform a single position measurement.
This mode can be used to extend the measurable range beyond that of
one sensor.
• Radial Cancel
(1)
- The two sensors are used together to perform a single
position measurement. The second sensor is configured to measure the
radial movement of the target. The radial movement is then subtracted
from the position measurement performed by the first sensor.
Calibration Bias Sets the zero or green position. The zero position is the normal
operating position. Setting the zero position compensates for the static
gap. This compensation enables the module to display only the
displacement around the zero position.
Use one of the following formulas to calculate the Calibration Bias. The
formula that you use depends on the Upscale setting and whether DC
High Limit and DC Low Limit are both less than or equal to zero.
• If DC High Limit is greater than zero, use one of these formulas:
– Upscale set to ‘Towards’ Formula
Calibration bias = Transducer DC Bias + (Sensitivity x Calibration
Offset) x sin (Target Angle)
– Upscale set to ‘Away’ Formula
Calibration Bias = Transducer DC Bias - (Sensitivity x Calibration
Offset) x sin (Target Angle)
• If DC High Limit and DC Low Limit are both less than or equal to 0,
use one of these formulas:
– Upscale set to ‘Towards’ Formula
Calibration bias = Transducer DC Bias - (Sensitivity x Calibration
Offset) x sin (Target Angle)
– Upscale set to ‘Away’ Formula
Calibration Bias = Transducer DC Bias + (Sensitivity x Calibration
Offset) x sin (Target Angle)
Volts
IMPORTANT: Check with the manufacturer about
operating thrust position and acceptable tolerances
before making any adjustments.
Calculate Bias (XM Serial Configuration Utility
only) Automatically calculates the Calibration Bias value.
Table 13 - Thrust position parameters (Continued)
Parameter Name Values are Comments
IMPORTANT The XM-124 module supports only Normal mode position measurements. If
Head-to-Head or Radial Cancel measurements are required, then the XM-
320 module (catalog number 1440-TPS02-01RB) must be used.
(1) Head-to-Head and Radial Cancel modes are not available in the XM-124. See IMPORTANT note, above.