Chapter 3
3-4 BiPAP® Focus™ Ventilator Service Manual © Respironics, Inc. REF 1029568 Rev A
Theory of Operation
Electronic System Components
User Interface PCB • Motorola 68332 microcontroller
• Inter-processor communication with controller PCB
• VGA Display, Keyboard and front panel LED Interface
• Primary alarm driver
• Remote alarm relay
• USB and RS-232 serial communication
• Internal Battery charging and monitoring
• Temperature monitor
• Microcontroller watchdog and reset logic
• Voltage monitoring
Controller PCB • Blower On / Off / Closed-Loop Speed Control
• Air Flow Valve Controller
• Pressure Measurement
• RS-232 Communication
• Inter-processor communication with interface PCB
• Backup alarm driver
VGA PCB • STN Blue Mode Transmissive Viewing
• One-Quarter VGA (320 x 240)
• Dot Pitch 0.36mm x 0.36mm
Table 3-2: Electronic System Components
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