Cleveland Motion Controls DIN Rail Amplifier MWI-13261 Ultra Series Isolated REV BA - Manual (Page 26)

DIN R AIL A MPLIFIER , MWI-13261 U LTRA S ERIES MAN-13261 U LTRA R EV BA
important to use a non-conductive tool to alter switch positions. Be sure that jumper-switch
settings are fully positioned, to avoid accidentally putting it in an “in-between” state.
3.8 A
DJUSTING
A
MPLIFIER
C
OARSE
Z
ERO
Two individual coarse offset adjustments have been provided. There is an adjustment for each Instrumentation
Amplifier channel because each transducer can have unique offset voltages. The Coarse Zero adjustments are
usually only adjusted one time, typically when the amplifier is installed, or transducers are replaced. Use the
following steps:
1. Ensure that the IA gain settings have been set as described in section 2.5.
2. Set the Zero potentiometer on the front cover to mid-way (approximately 9 turns from either clutch
actuation).
3. Set the Gain potentiometer from fully counter clockwise.
4. Temporarily place jumper switch J8 to the (2-3) position. This position excludes the RCH signal from
contributing to the analog outputs so that only the LCH zero is represented on the analog output.
5. Connect a DC Voltmeter to inspect the +/- 10 VDC output signal for the “Zero”
condition (NO calibration force on the transducers).
6. Adjust the LCH coarse potentiometer (P5) to achieve the desired “Zero” voltage. As this is a coarse
adjustment, a voltage within 50 millivolts of the intended “Zero” should be adequate.
7. Return jumper-switch J8 to the (1-2) position for normal operation (where the sum of both channels is
reported on the analog outputs).
8. Adjust the RCH offset using the RCH Coarse Zero potentiometer (P3).
3.9 A DJUSTING T HE LCH-RCH B ALANCE
This adjustment has been factory set for a “50/50” balance between channels. We recommend that you only adjust
the LCH-RCH balance if it is necessary to better match the signals from transducers having substantially different
output signals. To discourage unintended adjustment, the Balance potentiometer is located behind the access cover
and is recessed slightly behind the LCH and RCH offset potentiometer, requiring a more deliberate placement of the
adjustment tool.
Turning the Balance potentiometer clockwise, will boost the signal for the LCH and reduce the signal for the RCH.
Because of this, we recommend that you make any needed balance adjustments early in the calibration cycle. Adjust
the Balance potentiometer by observing the affect of an unequal application of calibration force upon the analog
outputs. When adjusted correctly, the measured force reported by the analog outputs should be insensitive to the
non-equal sharing of force between transducers.
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