Block Diagram Theory - Nellcor OxiMax N-600x Service Manual

Technical Discussion

Block Diagram Theory

150
The N-600x uses the information in the O
messages for the clinician. The O
oximeter the type of O
XI
to display, the pulse oximeter determines the O
recommended patient site for each model.
The monitor block diagram is shown below in Figure 22.
Sensor In
SpO
2
LED Drive
Sensor
Trend Data
LCD
Display
Buttons
Membrane
Switch
LED
Panel
Drive
Primary
Speaker
Secondary
Speaker
AC
Power
Battery
RS-232/RS-422
Analog Outputs
Nurse Call
The N-600x Main Board (PCB) consists of three (3) main parts:
• Secondary Input Port/Secondary Output Port (SIP/SOP)
• NELL-1A Oximetry Module
• User Interface (UIF)
The Secondary Input Port/Secondary Output Port SIP/SOP and the NELL-1A
Oximetry Module front end are both electrically isolated from the UIF. The
NELL-1A is electrically isolated to reduce capacitive coupling to earth ground
and improve the NELL-1A's ability to read difficult patient data. The SIP/SOP is
isolated as mandated by regulations for patient safety.
M sensor to tailor troubleshooting
XI AX
M sensor contains coding telling the pulse
XI AX
M sensor being used. When deciding which messages
AX
XI
NELL-1A
Display
Interface
Interface
Button
Contrast
Interface
LED RTC
Drive
Address
Speaker
Decoder
Drive
Frequency
& Volume
Power Control
LPS Board
Battery Status
Sync
RS-232 Data
SIP/
SOP
Figure 22: Block Diagram
M sensor type and
AX
Sync
Front End Reset
Patient Isolated
Power Supply
SPI Bus
RAM
Memory
Date/
Time
FLASH
ROM
Memory
Power PC
MPC823e
EEPROM
Reset
Watchdog
Power On
Reset