System A/D Values - Philips M3921A Service Manual

Diagnostic Mode
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When in the System Information screen, the wheel can be rotated to select any of the
changeable items. If one of those items is selected, a press of the wheel causes a pop-
up menu to appear. The first item in the pop-up reads
second item in the pop-up reads
accomplished in the normal manner, by selecting

System A/D Values

The System A/D screen displays the current value of each analog-to-digital (A/D)
channel in volts. Some of the channels are for AC-coupled signals (such as ECG
input), so the numbers on the screen are constantly changing when an input signal is
present. These AC-coupled values are shown to give an indication as to whether basic
functionality of the channel is present, but no significance can be derived from the
values of the numbers displayed. However, others of the A/D channels read DC
voltages, (for example, power supply voltages and battery voltage) and those voltage
values directly provide useful diagnostic information.
The Primary and Secondary Status messages from the SpO
updated at the rate of about once per second. Presence of the correct SpO
indicates that, at a basic level, communication between the SpO
monitor processor is working correctly. None of the displayed values can be changed
or reset in this screen.When in the System A/D screen, the Return item is always
highlighted; a press of the wheel returns the user to the Diagnostic Menu. Rotating the
wheel while in the System A/D screen has no effect. The A/D channel designators are
shown below.
42
Battery Deep Discharges:
System Software Version: Displays the revision level of the system software.
SpO Software Version:
2
operational. This value can be reset to zero, for
instance at the time when a technician installs a
new recorder.
Displays the number of deep-discharge cycles seen
by the battery. The monitor records a deep
discharge cycle when the battery volt-age reaches
5.6 volts, the voltage at which a
alarm is issued. This value can be reset to zero, for
instance at the time when a technician installs a
new battery.
The revision level is also momentarily shown on
the LCD as part of the Copyright screen. This value
cannot be changed by the user.
Displays the revision level of the software of the
MP-205 SpO module. This value cannot be
2
changed by the user.
Make no change
Reset to zero . Exiting the screen is
Return
Power-up Defaults Menu And Diagnostic Mode
Low Battery
; the
.
module are displayed and
2
message
2
module and the main
2