ConMed ExcaliburPLUS PC - Calibration and Adjustment Procedures; Calibration and Adjustments

4.5.7 Aspen Return Monitor (A.R.M.)
Calibration Check
This section describes the method to check the
calibration of the A.R.M. circuitry.
Equipment: Decade Resistance Box (DRB) with
attached dual foil return electrode cable. The
DRB must be adjustable from 0 to 160 ohms in
1 ohm steps and accurate to 1%. A dual foil
return electrode cable can be made by cutting the
cable to about 3 ft. from the connector from a
dual foil return electrode, and stripping the wires
for connection to the DRB.
NOTE: Some DRBs may present a brief open
circuit at the output terminals during switch
movement. This may cause the A.R.M. software
to calculate an erroneously high resistance read-
ing. This effect may be minimized by making
DRB setting changes quickly. If the resistance
read during any of the following tests is above the
upper limit, repeat the test carefully stopping in
each 1 ohm step for at least 1 second.
Procedure:
1. Disconnect all accessories from the Excalibur
Plus PC™ front panel.
2. Power up the Excalibur Plus PC™ in the
RUN Mode, and confirm that ASSIST Resistance
Indicator has all 10 green bars flashing, and that
the Return Fault Indicator and the Dual Foil
Mode Indicator are illuminated.
3. Using the test cable, connect the DRB to the
Return Electrode Jack.
4. Carefully advance the DRB in 1 ohm steps
until all 10 bars of the ASSIST Resistance
Indicator are flashing. Confirm that the DRB
reads between 137 and 163 ohms.
5. Set the DRB to 7 ohms and confirm that the
ASSIST Resistance Indicator is dark and the
Return Fault Indicator is lit.
6. Select Single Foil Mode. Confirm the ASSIST
Resistance Indicator stops flashing and the
Return Fault Indicator is not illuminated.
7. Increase the DRB in 1 ohm steps until an
audible Return Fault Alarm is sounded and the
Return Fault Indicator is lit. Confirm the DRB is
between 8 and 12 ohms.
8. Decrease the DRB setting in 1 ohm steps until
Te 411
the Return Fault Indicator goes dark. Confirm
that the DRB reads from 1 to 4 ohms less than
the resistance read in Step 7.
9.
Disconnect the DRB. This completes the
A.R.M. calibration test. If any readings were
only slightly out of range, first check the DRB
with an accurate ohmmeter. If the DRB is accu-
rate, recalibrate the A.R.M. limits in CAL Mode.
See Section 4.6. If one or more readings were far
from the mark, troubleshoot the A.R.M. circuitry
before attempting recalibration. See Section
4.7.6.
4.5.8 +5 Over Voltage Monitor Check
1. With power off, remove the RF shield and
place a short between A3TP3 (OVCHK) and
A3TP22 (+5). This will simulate the +5V supply
exceeding specified limits.
2. Turn unit on and confirm unit fails power-on
self-test (POST) and goes to an Err 22.0
(VBASE too low during POST). This occurs
because the simulated overvoltage turns VBASE
off.
3. Remove jumper, replace shield, and confirm
unit powers up normally.
4.6 Calibration and Adjustments
The Excalibur Plus PC™ is calibrated without
selecting or adjusting components. Instead, cali-
bration factors necessary to compensate for unit-
to-unit circuit variations are stored digitally in a
battery backed Nonvolatile Random Access
Memory or NOVRAM A3U2. The battery has a
lifetime of 10 years.
A special operational mode, called CAL Mode,
permits the NOVRAM data to be updated to
compensate for circuit performance changes due
to aging or replacement of components. In CAL
Mode, the microprocessor guides the technician
to simplify and expedite a complete and accurate
recalibration.
CAL Mode also provides microprocessor aided
diagnostics modes to help troubleshoot hardware
problems which disable the unit in normal ser-
vice, and can display the last fault code.