ConMed ExcaliburPLUS PC - User Interface Hardware

limiting circuit feedback loop, it is important that
calibration is only done with the proper load
attached. This will ensure that the unit is not in a
voltage limited mode and store the wrong
VBASE value. During ARM calibration, the unit
stores a value that corresponds to the resistance
attached at the return pad connector. There are
software limits to confirm that the resistor or cir-
cuit are within reasonable limits.
For each mode, the software checks to see if any
points have been changed. If at least one has, it
will require that all points that have not yet been
selected be activated. Points that have not been
checked are denoted by flashing the display when
those points are selected. An Err code 10.X will
occur if the power calibration menu is exited with
an incomplete calibration. Additionally, the unit
will check that all calibration points are monoton-
ic when the menu is exited, that is, it will verify
that successively higher power entries in each
mode are equal or contain successively higher
drive values. If not, an Err code 11.X will occur.
If both checks pass, the unit will calculate and
store a new CRC to allow verification that the
calibration has not changed and is stored properly.
During RUN Mode, the software interpolates the
drive value for the present power setting between
the calibration points. The drive value is then
passed to the VBASE Generator or Waveform
Generator necessary to produce the set power.
3.4.3.2 Diagnostics
Sections 4.7.1 - 4.7.3 contain the details for the
use and operation of the diagnostic modes avail-
able from the CAL menu.
3.4.3.3 Last Fault Code
The microprocessor will store the last fault code
that caused it to shut down in Run or Pseudo
Run mode. From the top level Cal menu, LFC
can be selected for viewing, and to clear the pre-
sent code. See Section 4.7.1 for additional details.
3.5 Display Hardware
The Display PWB Assembly (A2), in conjunction
with the Membrane Switch Panel (A1), is the
user interface to the unit for all inputs except
ibyrPlus,PC”
hand or foot controlled activation requests,
Power settings, mode requests, and return elec-
trode alarm set point are all entered via the front
panel membrane switches. The various indicators
and displays supply machine operating status.
These include requested power, mode, program,
return electrode resistance, and alarms if they
occur,
3.5.1 Indicators
Refer to the Display Schematic 4.3. The control
of the indicator lights on the Display PWB is
handled by the Peripheral Interface Adapter
(PIA), U3. Address, data, and control signals are
supplied to the PIA from connector J1. This
device contains three registers (one for each Port),
which can be individually written to or read from
by the microprocessor. The three I/O ports are
allocated as follows.
PORT A (PAO - PA7). This port is connected to
the octal DRIVER, U5, which controls the num-
ber of Bar LEDs that are illuminated in 122, the
“ASSIST Resistance indicator” display. By writ-
ing a one to any of the eight inputs to US, the
corresponding output goes low, turning on the
LED. Note that the first two LEDs of 122 and
the last two LEDs are connected in parallel to the
output of US. This is done to interface the ten
bar LED readout to the single byte output of
Port A.
PORT B (PBO - PB7) and Port C (PCO - PC7).
These ports control the various modes, activation,
and alarm indicators. Whenever there is a one
(high) written to a Port line, the output of the
corresponding driver will pull to ground turning
on the LED or lamp.
3.5.2 Displays and Keyboard.
The control of the 7-segment displays and the
keyboard is performed by the Keyboard/Display
Interface, U2. Scanning of the keyboard and
multiplexing of the displays is implemented by
the outputs SLO - SL2 counting in a binary fash-
ion which is decoded by U4. The outputs of the
DECODER and Driver (U4), go low sequential-
ly (0, 1, 2, etc.) scanning 11 - 18 displays and
both
rows of the keyboard. Transistors Q4 - Q6,
which connect the scan lines to the keyboard
[= 3-11